Brandondrury,
In comparing the AT4060 to the L251, the short answer is, of course, it depends. I prefer the AT4060 for more sibilant vocals and guitar cabinets. I prefer the L251 for most vocals and room mic. I haven't compared them to other things. The L251 is more flexible because of the infinitely variable polar patterns. The AT4060 is a fixed cardioid mic. The L251 is about twice as much as the AT4060, but you know, they're both nice mics. The L251 has that wonderful top end, whereas the L251 is very neutral sounding, and that's one of the reasons why I prefer the L251 for vocals in general, but again, there are applications when pulling out the AT4060 is better. If I had to own only one, I would choose the L251. I can't begin to tell you how lucky I feel that I own both of them.
I think that the AT4060 sounds nicer than the AT4033. It sounds fuller, and there's something about the midrange that sounds more pleasing to me, but I'm not sure what since I've never done any head-to-head comparisons. The AT4060 isn't what I would call an "exciting" sounding mic. It's very smooth and neutral sounding, and doesn't sound like what people associate with a tube mic (whatever that is). It's quiet, smooth, and neutral.