If you have an ipod touch or iphone and don't know what apps to download, here are some recommendations. The prices might change because of sales, but most have a free version.
Tap Tap Revenge (free)
In my opinion, this is the best free game. It's similar to games like Guitar Hero or DDR, but you're using your fingers instead. It comes with some songs and you can download more with wifi.
Labyrinth (lite is free, full is $2.99)
Navigate through a 3D maze with walls, holes, and other obstacles. The new version of Labyrinth is a big improvement over the old one, and it's definitely worth buying the full version - there are a lot of levels to choose from.
Crash Bandicoot Nitro Kart ($2.99)
A fun, Mario Kart style racing game. You tilt the screen to drive around the racetrack and try to beat the other characters.
Frenzic ($0.99)
This game starts out slow but becomes more fast-paced. There are 6 circles that each hold 6 pie-shaped pieces. As a piece shows up in the middle, you have to tap a circle with an empty space for it. You can get extra points for matching up pieces that are all the same color.
Icy Escort ($0.99)
This, along with other Donut Games games has amazing graphics. You are a penguin moving across platforms, trying to get to your baby penguins. You can pick up ice cream along the way to get more points.
Sally's Spa (lite is free, full is $2.99)
One of my favorite games. It's an addicting time management game and the graphics are great. As a spa owner, you have to drag your customers to where they want to go (like a sauna), move them around the spa, and then collect money. Between levels you can shop for new items.
Chocolate Shop Frenzy (lite is free, full is $0.99)
Another time management game, only this time you own a chocolate shop. Make chocolate boxes, animal-shaped chocolates, and more for your customers before they get angry and leave. I love the graphics in this game as well.
Cooking Dash (lite is free, full is $2.99)
Yet another time management game :P Make food for your customers, like fries, steak, frozen yogurt, and more before they get impatient. You also have to clean dishes when they are done eating and collect money. You can shop for items like new ovens between levels.
Rat On The Run (free)
Navigate through various platforms to get cheese for the rat. You keep moving until you reach a stop sign, and there you can choose whether you want to go left or right. Watch out for spiders and sharp blades.
Tower Bloxx Deluxe 3D (lite is free, full is $0.99)
Build a tower as high as you can using seperate blocks. Tap the screen to set them down, and try to get them as close as you can to the ones below, or your tower will fall over.
Super Monkey Ball ($3.99 or $9.99 for the new version)
I have the older version, and aside from the controls being hard to get used to, it's a good game. You play as a monkey in a ball, rolling around different scenes to get to the end. The newer version apparently has better controls, but it costs a lot more.
Shake and Spell (lite is free, full is $1.99)
Similar to Boggle. You can choose the time limit, then make as many words as possible from the letters you are given.
Waterslide Extreme (free)
Steer your way through a waterslide above a city. Not my favorite, but it's good for a free game.
Fling (lite is free, full is $0.99)
Very cute game with great graphics. Use your finger to push the furry balls into each other and off the screen. The object of the game is to get all of the furballs off the screen except for one.
LineUp (lite is free, full is $0.99)
Different colored blocks show up on the screen, and you have to get rid of groups of matching colors (3 or more blocks) before they reach the top of the screen. I suck at this game but it's fun anyway.
Sudoku (lite is free, full is $2.99)
Sudoku frustrates me so I don't know why I have this app :P But if you like sudoku, you'll like this.
Santa's Rollercoaster Rush (lite is free, full is $0.99)
A Christmas themed game. Control the speed of the rollercoaster as you ride it. This game gets repetitive but I think it's a good game to download around Christmas time and delete later.
Pandora Radio (free)
Find new music by typing in an artist you like. Recommended songs will start playing, and you can give them a thumbs up or thumbs down. If you hear a song you like, you can bookmark it.
I Can Haz Cheezburger (lite is free, ad free is $0.99)
Funny pictures and videos from I Can Has Cheezburger, Fail Blog, Loldogs, Pundit Kitchen, Graph Jam, Totally Looks Like, Engrish, ROFLrazzi, and Once Upon a Win.
F-MyLife (lite is free, full is $0.99)
View updates from fmylife.com. You can't comment or moderate on the free version, but if you just like reading the updates, don't buy the paid version.
Twitteriffic (lite is free, premium is $4.99)
Twitter addicts will enjoy this app. You can post updates and @replies, view trending topics, etc. The bird is really cute.
Koi Pond ($0.99)
This has very realistic water effects. Shake to feed the koi fish.
Scribble (lite is free, full is $0.99)
Draw on your screen using your finger, and save your images to your photos.
iScopes ($2.99)
My mom always steals my ipod to read the horoscopes. If you like reading horoscopes daily, get this app. I thought it was free, but I just checked and it's $3 now.