Here's a couple of links with different cast-ons, telling you what they're good for and pictures of what they look like, so you can narrow down what you want for your garment:
http://www.knitty.com/ISSUEsummer05/FEATsum05TT.html
http://www.knitty.com/ISSUEfall05/FEATfall05TT.html
There's also a lot of specialty cast-ons out there. For instance, here's two very stretchy ones:
The German Twisted Cast-On:
http://knitting.about.com/od/casting...an_twisted.htm
The Channel Island Cast-On:
http://www.haveayarn.ca/stitch/08_20..._the_month.htm
Have fun!