Valistroke It's a really fun puzzle game that tests your reaction time/perception skills. Your objective is to draw a continuous line through the numbers, and then reach the goal at the end. You have to do within a time limit, of course. It's randomly generated every time. My only qualm is that you can't pause in the middle of the game.
Spirit or Spirit HD, no demo but believe the 5 stars comments (and vow to hell others ), that's a great game. Very original game, levels random generated. I usually don't like much random generated because it's never a design as well tuned than human designed levels. But it works rather well in this game. Another cool thing, it alternates phase where cold blood, precision and thinking is the best, with phases where fast reaction and quick decision are your salvation and phases where you can take all your time and apply your patience for lower risks. Also the gameplay is quite deeper than you could think at first. Current negative points are difficulty a little high and learning curve a little slow, and the abstract graphics if you are a graphic whore.
Crosswords is worth it to me (I held off for months!) because there are new puzzles that you can d/l every day from a whole slew of newspapers. I would warn you though that most of the puzzles are probably on the level of NY Times Tues - Thurs though, so if you are a Monday person (like me) there are generally only 1 or 2 a day that I can solve without a lot of hints. That being said, I don't generally do more than that ever... Word Quest Pro screenshots don't really do it justice unfortunately. The UI does have some issues (with clutter as you mentioned) - but I have e-mailed the dev and he is going for having 1 screen rather than multiple nested screens... His preference - a really excellent word search game though - and the additional games are quite unique and challenging. Vexed is by a different dev than Vexed DLX, so if you like it, get it from that guy. The advantage of the Vexed DLX is that it is universal. The Vexed edition scales up just fine if you have an iPad. The word games that come to mind are things like Text Twist, Jumbline (my favorite due to being able to underline rather than tap letters - their lite version is TERRIBLE though - ads, timers, almost trying to drive customers away), Chicktionary (there is a free version of this through MS)... Good luck in your quest.
Although I am looking for a - Puzzle - Side-Scrolling - Adventure type game that never ends. hehe. Helsings fire Fastar? Solomons keep