Live or recorded? If you want recorded then you really want the best condenser you can for your budget. A little research goes a long way. If you consider the frequency band of the human voice, and then compare it to the microphones frequecy response you can get a general picture of how the sound will turn out. It really depends on you budget though. The AKG C414 is the most versatile condener I have ever used, but at £700 each, you hope so. The C214 is a good alternative, although it ony has a cardiod polar pattern. Neumann U87 are another classic, but then you're looking at over a grand. The SE Electronics z3300 is the cheapest, fairly decent interchancable polar pattern microphone I've found, and you can get good results from them. Audio Technica do some good condensers for around £150.
Live? SM58 all the way. It's industry standard for a reason.
I've been in and out of studios for the last five years learning out this microphone and how they work, let me know if you need advice/fancy a good discussion.