I so love my ipod Touch, although it's a bit dangerous as all I can think of now is how much better an iphone would be for the 3g capabilities.
My apps -
Productivity Apps. Most of these were free or .99 at most
Tip Calculator
WiFi Track - to find WiFi zones
Convert Units
iHandy Level - I've used this more than I thought I would.
Flashlight
Aji Reader - PDF reader
Alarm Clock
Stitch Minder - I knit, and love this freebie app to keep track of rows.
Shopping/Reference Apps - Again most were free or really cheap
Facebook
IMDB
Amazon
Southwest
Target
Redbox
WootWatch
La Quinta
Ebay
Electra - Bicycles
MLB at Bat
Pizza Hut
Alice
eTicket WDW - one of the only ones I've paid more than a dollar or two for
Fun and Games - most picked up when free
Kindle - (Can't live without my Kindle app on my ipod)
Monkey
Solitaire
BirdStrike
SimonClassic
Brain Trainer
Impossible
Twilight
Etch a Sketch Lite
Doodle Buddy
Tap Tap Revenge
iSpades
Frogger
Dots Free
Minesweeper
Skee-Ball
Crack Code
Hunt the Wumpus
Falling Balls
The Simpsons - I think my most expensive app at about $4 or so
Toy Story Mania
Phineas & Ferb - My favorite game on my ipod. Well worth the money.
Disney
White Noise - Helps me sleep with different noises. I love the waves.
Sleep Cycle - Love this one too. Wakes you up gently, and shows your sleep patterns
Eternal Fire - fake fire, a freebie.