You're trapped underground where you'll encounter varied and sometimes hazardous plant life. Jetpack through tunnels, planting seeds, bringing a complex-yet-intuitive ecosystem to life. This one has great visuals, touch controls and a gradual learning curve. Botany is fun.
At 99-cents, Puzzle Juice is a cross-genre word and puzzle game. It will remind some of Tetris, perhaps Bejeweled. Ever done a word search? Try playing all three at once or just play Puzzle Juice. It's stressful, but it's entertaining stress.
The 99-cent Sky Gnomes is a race against the clock. Gnomes fall to the ground in this customizable racer. Steer your ship to collect coins and snowflakes, while avoiding rain and sunbeams. Each race earns points, speed-up your progress by coughing up real-world cash. The game's online league system promotes you to a tougher division if you outperform too quickly. The real challenge is stopping yourself from taking "just one more dive."
Zombies have been in the news a lot lately. At two-99, Plants versus Zombies lets you slay the undead in mass numbers. The only way to defend against the zombie hoard is with backyard plants grown by harnessing sunlight. A "wall-nut" will delay your common flesheater; if they pole-vault, shoot them down with snow peas. This one is a hoot.
At two-99, You Don't Know Jack is more for adults. It's game-show style trivia. This one has been around since the 90s and still plays well. Quick-hitting multiple choice pop culture trivia in a pseudo-TV game show format. The narrator adds lots of color commentary and his jokes are usually funny.
Finally, a free one, Triple Town. A PC fav and a good iPhone match. Populate a town by matching up grass, trees and buildings. You'll have to contend with limited space issues and lots of very annoying bears. You can play for hours on end without dropping a dime.
Others worth considering:
Hero Academy, free
Dungeon Raid, $2.99
Beat Sneak Bandit, $2.99
World of Goo, $2.99