I keep a 57 in my case, just in caseUpawholestep said:Shure SM 57. About $90 new and can take a lot of abuse (physically and sonically). Keep it in the pouch that it comes in and throw it in your gig bag, you'll never have any problems.
You can find them a little cheaper than that. It's not a clip on obviously, but it's probably the most popular live mic around (and it's brother the SM 58 for vocals).