Honestly, if I were that type I'd probably do Lincolns. That's because I *am* the variety-hunting type, and Lincolns abound in the miscellaneous little doubling and stuff that floats my boat.
I would go with the cents as well. I too enjoy looking for RPM's and Double Dies. I always get a few "wheat" cents and a couple of times an Indian cent. Second choice would probably be halves. Seems like the best shot of finding some silver. Even if it's only 40%.
I like dimes because of 1981-P for six bucks and all the other varieties. Also the occasional silver dime.