I vote Charollais - easy lambing, lambs grow really well, great conformation, weigh well for their size, tasty succulent lean meat
Lovely fleece too, if you spin. Tups generally pretty placid - although very greedy and can knock you over in their greed
Only downside is the lambs can be fairly bare-skinned (which is one of the things makes them easy-lambing) - if this is an issue where and when you lamb, get a tup with plenty of wool on his head, and keep those plastic lamb jackets handy