There is no surprise
The problem is, there is almost no surprise at all.
PC Games today seem mostly to be variations on the same theme. They may get better AI, better graphics, better sound, but there is no new concept, nothing relly new, no creative and innovative ideas.
They all look and play more or less the same. The games don't grow on you. They don't reward you, they don't give anything new.
There are one or two new ideas here and there, but used only in little details. Like Max Paine. Bullet time was a good idea, it kick ass, and can be quite handy sometimes. But then what, just an FPS with some comics instead of cutscenes.
And every little idea is reused again and again..
Ok I liked Half-Life, but I couldn't play any other HL game. I tried Opposing Force and Blue Shift, and both were just the same game. I thought: "hey, I have already played this game", and killed both.
The same happened whith Quake I, II and III. I bought Quake I and played it to the and. Nice graphics, but Doom is a lot more fun. Then I bough Quake II and never played to the end. Boring - I thought. I tried Unreal Tournament and I was pleased, since I have never played on-line/multiplayer deathmatch games. But when I loaded Quake III, it played just as UT. Different places and weapons, but the same gameplay.
And what about RTCW and MoH? gee they look (and play) almost the same. But MoH has at least the D-Day at Omaha Beach, and it kicks ass. I played MoH to the end, but now I can't play RTCW because it makes me sleep.
The last RTS I've played to the end was Warcraft II. I missed Total Anihillation and Starcraft, but all recent RTS looks like Age of Empire with different buidings.
I love games, I love PC games, I love a lot of PSX games, and a even bigger lot of retrogames, but I can't deny there could be a lot of more innovative ideas. But companies keep feeding us with the same proof-tested games formulas.