I'd suggest a Shure SM-58 BETA(!). Try finding one used, or invest $20 more for a new one depending on your situation. I wouldn't bother with a hardware mic pre-amp, try some VST plugins first!
There's a lot of pro's saying that you'd have to buy a really really really good condenser if you'd want to beat the SM-58 BETA soundquality wise.
^Actually, it's called a Shure Beta58a. And I completely agree with this suggest UNLESS you don't have a warm, round tube preamp. Otherwise, run away. That mic is absolutely useless without one. Also, suggesting not to bother with a hardware preamp is a terrible suggestion. A good mic preamp will make MUCH more of a difference than a microphone.
I'm also not sure where you got that "pros" statement, a real pro would never compare a dynamic microphone with a condenser like that. At least none of the pros I've been trained by.
Get a used AKG C1000. Might be a bit over your budget, but it can record literally EVERYTHING from high gain guitars to singing to hard vocals to acoustic guitars to ambient noise. It's a do-everything-very-well microphone.
Its mostly about making a vocal booth for cheap - but further down the thread is a great example of utilizing a sm58 by taking the top off and some other creative techniques.
Also - I know you said $100 buuuuuut i've tried and tried to tell people about the Studio Projects C1 ......but it usually falls on deaf ears. It is a HUGE bang for the buck!
Thanks guys! Now that I have many suggestions for microphones, what pre-amp do you recommend? Remember that I dont need "Pro" sounding stuff just something to get the job done medium-well.