I like Californians because they are so calm and loving...I've never met a mean one. Chinchillas are very outgoing and friendly, too. The lop breeds tend to have good temperments...they were the first breeds that people really started keeping as companions.
As a general rule, larger breeds tend to be calmer. I've found that the breeds used for meat (such as New Zealands) are especially calm. Angoras have awesome temperments...after all, they have to since they need to be groomed so much.
But really, it depends on the individual rabbit. Miniature Rexes are known for their friendliness but there are some that are probably very shy and skittish. At the same time, dwarves are known for being nervous and tempermental but some are extremely sweet and cuddly.
It also depends on whether your rabbit is spayed/neutered. A fixed bunny is a better behaved and friendlier bunny
And one more thing that many people seem to overlook....it depends on where you get the rabbit. Just like with dogs some rabbit breeds are popular and therefore are bred like crazy...mainly by backyard breeders and rabbit mills. For example, Holland Lops are generally easy-going, happy rabbits. But one from a petstore may be badly bred and un-socialized. If you want a certain breed for certain traits it's best to go to a good breeder.
If all you want is a friendly rabbit then just visit your local shelter and see which bunny you like best
Oh, and as far as intelligence go Belgian Hares are known for being extremely smart. But they are pretty rare.
Remember that no matter which breed you choose very few bunnies like being picked up. And you can't expect the rabbit to love you right away...you need to earn their trust