I really like my SF4 Tournament Edition stick from madcatz. One of the more expensive retail options (excluding the $300 hori options), but easily the best quality.
You can get it for closer to $100 if you look for sales and such:
http://www.amazon.com/Xbox-360-Stre...WKXM/ref=sr_1_1?ie=UTF8&qid=1296170828&sr=8-1
Originally, I picked up a pair of these to play soul calibur 4 with. They are really fun, and much better than the controller in terms of fun factor, but they *feel* cheaper when compared to the T.E.
Before SF4 came out, you could find these for $25-40 bucks, but now they are way expensive again, due to the re-popularity of street fighters.
http://www.amazon.com/Xbox360-Fight..._2?s=videogames&ie=UTF8&qid=1296170873&sr=1-2
I don't know much about this stick, but it's bundled with tekken 6 ($10 value):
http://www.amazon.com/Tekken-Limite...4DQI/ref=sr_1_5?ie=UTF8&qid=1296170802&sr=8-5
In all honesty, if you want *a* stick, I'd go with the T.E. Just look for a sale on a new one for around $100. The main problem with getting a T.E. is your friends will complain that you get an advantage, and that you should buy a 2nd one so the competition is "fair."
Check around and do some quick research to see if any of the T.E. sticks are better than others. I think they are all about the same besides artwork, but I don't know that for fact.
Note: T.E. stick is also awesome when used in conjunction with Scott Pilgrim and Xmen arcade games. Not so much with Castle Crashers, since casting magic is a built more for the controller.