honestly i'd go on youtube and listen to recording samples of the different microphones as this is the best way for you to figure out which you like the sound of.
quite simply all of the ones you listed are suggested microphones for people on a budget and any of them would work.
now, from what i've heard and the samples that i've listened to the c01u has decent quality but tends to pick up a bit more background noise than the snowball which is why i personally rated it below the snowball. some people have a volume issue on the snowball and i thought the 2500 sounded better which is why i rated it below the 2500.
issues i've heard of with the various models:
c01u - picks up more background noise
snowball - on some computers it seems...