what do you want it for??? mcing at raves? singing in the studio? micing a guitar amp? recording the sounds of your neighbours shagging through the wall?
mics are generally suited to different tasks.... although, from what i read, its seems the shure sm57/58's perform well for a whole manner of tasks...... they are used by some of the best engineers in the world as well as in bedroom studios...... not that expensive either
oh, another thing..... it depends whats compatible with your preamp/mixer?? if it doesnt have have 48v phantom power then that mainly limits you down to dynamic mics (i think ribbon mics have no need for phantom power either but i know absolutely nothing about ribbons so im not evn gonna go there)
also, you gotta think about your inputs, but then again adapters can be found on ebay for next to nothing
for studio mic-ing, vocals or amps, the shure sm57 is good and my mc friend recommends it for the 100 USD range. but for live stuff, i got the sm58s (which is the sm58 w/ the on/off switch) w/ a cable for 100-115 USD (dont remember price exactly). also came w/ a mic stand clip and a bag. its good stuff.