English Amiga Board - easiest and best game creator ?

Here are my 2 cents regarding your options:

Backbone
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Pros:
1) The most easy and user friendly game maker on Amiga (at the moment).
2) Offers a nice amount of options and a few examples to start with. You can create simple platformers, top-down stuff, shooters and even light rpgs with it.
3) Good choice for someone who just wants to experiment with Amiga game making (without coding) and see what it's like to create a simple Amiga game or demo from start to finish.
4) Erik's Scorpion Engine and it's Backbone to Scorpion converter option has made using Backbone a bit more relevant, as you can start with it, create the basics and then move to Scorpion for better performance and more options. However Scorpion is at the moment a work in progress (more on that below), hence this converter option is still incomplete and not released yet.

Cons:
1) Really bad performance. Expect jerky scrolling even if you use the lowest color count, low screen size and 060. In general, if you use 16 colors, a lower resolution and a low enemy/projectile count on screen (and scrolling aside), you could get tolerable results on 030 even 020.
2) The program itself is not finished, there are various options included that partially work (or are simply broken) and numerous bugs that make the process harder and often produce furstrating results. While with some issues there may be ways to bypass them if you experiment a bit, others you simply cannot. Hopefully there's a good amount of help you can get (check f.e. the "Amiga game factory" section here on EAB).
3) Good as the options in offer are, you are still limited in what you can do (gameplay and game design wise). F.e. if you don't like the way Backbone handles shooting, well, you are stuck with it. This means that the range of games with special gameplay features you can create with it is not really that big.
4) No AGA support

Reality engine
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Pros:
1) Another 'easy' to use game maker. Less user friendy than Backbone though.
2) In general you can get better performance with it vs Backbone.
3) Since the engine's concept relies on tweaking the pre-made game examples that come with it (and these are ok made to begin with) you can get tolerable quality results, in many cases better than what you could make with Backbone.

Cons:
1) Still the performance output is mediocre compared to any other option out there.
2) The features the program offers are very few and very limited. Practically (as already mentioned) the engine comes with genre specific games as examples (like f.e. one platform, one shooter e.t.c.) and allows you to reskin them as you like and tweak them a bit. However in general there's not much room to do your own original game. In that regard, Reality engine is severly limited, even compared to Backbone.
3) Not a huge amount of info about it is out there and not much help you can get.
4) No AGA support

Redpill
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Pros:
1) Brand new, all in one, Amiga game making program. Easy to use but can be a bit more complex than Backbone (at least at first glance).
2) Afaik this is the most flexible and option loaded Amiga game maker. While it's slightly more tricky to get into, it allows for a ton of different genres and unique game design features. In that regard it's more akin to modern game makers on PC than any the Amiga has seen so far.
3) There's a lively community here on EAB you can check for help and Zener (the creator) is a regular on these forums and offers tips and support.
4) Partial AGA support (AGA colors) at the moment.

Cons:
1) Redpill is still a work in progress project and hasn't seen a final release yet. While the program is already packed with options, can produce full games and gets regular updates that fix issues and expand it, many may be sceptical to fully invest into it until it reaches that more complete state.
2) Performance with Redpill is -at the moment- a mixed bag. While it's nowhere near as poor as Backbone, you still need a beefy setup if you start loading the screen with stuff. This is something that might get much better with future releases but remains to be seen for now.

Scorpion engine
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Pros:
1) It's a new, windows based, Amiga game making engine that works with other modern PC programs like Tiled, Spriter beta and Ink.
2) This is (perhaps) the best performing game maker for Amiga I've seen so far, offering 50fps scrolling on 020 and a good output even on lower spec machines.
3) The program, has a nice amount of options, making it possible to create various different games like platforms, shooters and light rpgs (just like Backbone). However it's much more limited compared to Redpill at the moment.
4) Scorpion has recently been upgraded with a Backbone converter. This means that you can create your game in Backbone (if you really preffer to work on Amiga instead of the PC and the programs on offer) and convert it to Scorpion to make it perform better, or expand it further using Scorpion's more advanced options.

Cons:
1) Scorpion's biggest issue is that it's an extremely early, work in progress project. You can tinker with the latest build, game examples and it's options a bit, but that's all for now. As Erik constantly expands and re-configures the program and it's structure, many of the features for each version may be changed signifficantly later on. So, overal it's not really recommended if you want to start building a game from start to finish, right here and right now. Things might change in the future though.
2) It's probably a lot more complex to get into than any of the above Amiga game makers. Stucture and option wise it allows for complex, pro-dev tinkering, but it has a steeper learning curve (at least compared to other, simpler Amiga game makers). Also it's not an all-in-one package, as it depends on external editors (like Tiled) to do basic stuff, so you'll need to know how to operate those programs as well. Currently, a unified UI is being created (still windows based) to make it more user friendly but that's also in very early stages.
3) No AGA specific support (for now) but that might change in the future.

GRAC
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Your best bet (in regards to game makers) if you want to create adventure games. I can't really comment on how easy it is (as I've never used it) but it looks a lot like Backbone and it seems to offer just about everything you'll need to create your own adventure game. There are many nice titles that have already been made with it (like f.e. Epsilon 9 and the recent Retro Wars, if you want to take a look at what the program is capable of).

SEUK
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Geared on shoot-em-ups and released at '89. Never used it or seen anyone using it, hense I cannot comment on it either. 'Blood and bullets' is one small game that has been created with it if you want to check it out on ytube.

Programming
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It is a moot point talking about programming since the first post clearly states : "Coding seems impossible for me for some reasons...I'm looking for the easiest amiga game maker". However I really feel the need to leave a couple comments here.

-Imho, Amos is definitely capable of producing stuff that can stand face to face with other productions and (dare to say) often on a professional level. It's surely not as powerful as other languages, but there have been a plethora of games made with it that have excellent performance and zero to envy from other commercial titles. It all depends on what you want to do and the game you want to create (and obviously how good of an AMOS programmer you are). If you want to make a graphic adventure or say a dungeon crawler, or a game with not a huge amount of activity on screen, then AMOS is brilliant. Plus it's quite user friendly for enyone that has zero coding experience, so it's an ideal starting point. Here are a few known technically excellent AMOS games: BabeAnoid, Flight of the amazon Queen, Jetstrike, Timekeepers, Valhalla series.

-Blitz is on a completely different league. Not as user friendly as AMOS but much more powerful. Worms, Worms DC, Roadkill, Skidmarks, Super Tennis Champs and Foundation are a few commercial titles made with it. Do I need to say more?

-Between AMOS, Blitz and ASM there's also C. Extremely powerful in the right hands.

-ASM is obviously the "king of the game" but you really need experience to get into it. There's no doubt we need more ASM coders, however it's hard to advise someone to start with it when he has absolutely zero programming knowledge. Especially if his only interest is to start making simple games pronto. You can't honestly expect someone to become a PhD chemist if he just wants to experiment making lemonade. Can you? ;)