Lookin for a good bag or two...

I've been searching various Goodwill stores for bags for our Go-Kits.  I don't know why I'm being so picky about it, but I really just want something CHEAP that is both comfortable and functional.  The best backpacks I have around the house are already in daily use and they are not cheap.  I also want something a little more fun for my 10 year old son.  Next search will be online!