Hmmm.. I'll go for both Secret of Monkey Islands.. I haven't played the new ones, but the 1st and 2nd games are just top notch, good puzzles, nice plot and one joke after other... I love them.
As for text adventures... I liked Hitchhiker's guide to galaxy, Adventure Quest (from Level 9) and Cobra's Ark (from Dinamic, I dunno if many people know it, I think it was released only for Spectrum and MSX ) ..... The last 2 have graphics, and cobra's ark even have a kind of icons interface , but both are text-adventures at heart .