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In terms of design:
1. Transmit
2. Acquisition
3. iTunes
4. Safari
5. CSSEdit

In terms of what I use daily:
1. iTunes
2. Xcode/Interface Builder
3. Transmit
4. SubEthaEdit
5. Shark
 
My favorites, excluding the Apple-made applications I have that came with Tiger, came with my Mac, or I purchased separately:

1. SuperDuper!
2. WMV Player (by Flip4Mac)
3. Colloquy
4. UnRarX
5. Dome Wars (it was tough to determine #5)

The same list, including categories excluded above:

1. SuperDuper! (wins by a HUGE margin - more than worth the shareware fee)
2. iTunes
3. Mail/Address Book/iCal (tie)
4. TextEdit
5. Safari
 
  1. Quicksilver
  2. iTunes
  3. GoLive (and the other adobe apps)
  4. Growl
  5. Dashboard, nah, make that Adium. Dashboard is still cool though ;)
 
1) Safari
2) Adium
3) BitTorrent(Tomato Torrent)
4) Itunes
5) MS Office

This doesent include things i consider to be part of the OS(Dashboard(useless) Expose(really helpful) etc.)
 
Most Used:
1.) Word
2.) Safari
3.) Dictionary
4.) Mail
5., 6. and 7.) iTunes, Keynote and Photoshop (all tied)

Favorite to Use:
1. and 2.) Keynote and Dashboard (tied)
3.) Photoshop
4.) OmniGraffle
5. and 6.) iTunes and Word

Most Needed with No Equal of Better Alternative:
1.) Word (Nothing Comes Close Including: Pages, AppleWorks, TextEdit, Open/Neo Office)
2.) Photoshop
3.) Dashboard
4.) Dictionary (because of the ctrl+cmd+d feature)
5.) iTunes
 
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