i've never grown white widow, but i've actually heard they're pretty finicky.
i'd say something like northern lights for easy yet potent. bermese is pretty hardy also. my buddy's hawiian are pretty tough plants too (very very smelly strain though.)
really though, marijuana is a pretty tough plant.
*i've not grown a lot of different strains unfortunatly, so can only advise on what i have.. some of the other members will probably give you a good list though. i say just go for what you've tried and liked.