Boa constrictor or red tail
Dumeril's boa
Carpet python
Brazilian rainbow boa
Don't forget the dwarf Boa's as well, like Hogg Island Boa, Sonorans, Crawl Cay's, Caulkers Cay's and Pearl Island and Nicaraguan to name a few.... These only top out at 4-5ft at the most (depending on sex) but still have the wonderful character of larger Boa's.