If I was looking only at that list, I would immediately eliminate C3000B, which I dislike on almost anything, especially vocals. The other four are all pretty good mics *for somebody*. The NT1a I have never used, but lots of people speak highly of it, and my experience with Rode customer service (I own an NTK) has been excellent. I had a problem with the NTK's cable, and they replaced it quickly, for free, no questions asked. I can't bitch. The B-1 I own, and I don't really use it much, not because it is a bad mic, but for what it does, I simply have better mics, and the comparison isn't fair, because the better mics all cost a lot more. Frankly, I consider the B-1 more of an instrument mic than a vocal mic. It is pretty clean, not much color. If the singer is really good, so is the B-1. For that kind of mic, mostly I use a C414 (I told you it wasn't fair). I would probably use the B-1 on a piano or a mandolin before I would stick it in front of a singer. The V67 is another mic I don't own, but many people on this board like it for male vocals. It is reputed to be a little darker than the usual run of cheap Chinese condensers.
The C2000B is a whole different animal. It's a cheap mic I use *all the time*. Unlike the others, it is a small diaphragm mic, but in a larger housing, which makes a huge difference in its response to a variety of sources. My best comparison is that C2000B sounds like an Oktava MC012 (one of the better ones), except that unlike MC012, it is not prone to popping, which makes the 012 almost impossible to use as a vocal mic (like most pencil mics). It has a fair amount of color, like the Oktava. In other words, I would be more likely to call it flattering than honest. Where I would put up the C414 and/or Neumann KM184's on a $5000 acoustic guitar, I would put up the C2000B on a $200 guitar, and it sounds great. It is a stellar percussion mic, good as an overhead, on toms, conga, djembe, chimes, cowbell, whatever. It is an excellent cab mic, sometimes alone, and sometimes with a dynamic, depending on the cab, and the sound I want. In short, from your list, I would choose the C2000B, not because it is so great on vocals (and it isn't bad at all), but because it has so many *other* uses. No vocal mic works for everybody, including major-league main vocal mics, and I can't afford to keep mics in my little studio that have only one use. The C2000B has stuck around because it is the right mic for some singers, and when it isn't, it's probably good for something else, more often than not, a cab.-Richie