#2
The Blue Snowball is pretty nice, but I haven't been able to try any other USB mics so I can't compare.
#4
^^ yeah, i tried that for a while until i think i blew the soundcard or something o__O?
it still plays music fine, just when i record straight into the computer it sounds like fuzzy...i dunno, intolerance.
#5
Samson do a few nice USB mics.

http://www.samsontech.com/products/brandpage.cfm?brandID=2

The four of five models they do are listed on that page. Friend of mine has the CO1U or the CO3, they are pretty good sound quality.
Main Gear:

Santiago S3 Spanish Classical
PRS CE22 Mahogany
Mesa/Boogie F-50 combo w/ G12K-100
Teese RMC Wizard Wah
Rothwell Switchblade
Ibanez FL-9
Visual Sound Liquid Chorus V2
EHX SMMwH