I own both Leos and a Beardie, and the BD is more active.(at least mine is compared to my Leos) This may be the case because Leos are nocturnal, so when they ARE active, we just arent awake to see them. you can have fun with both, both can be handled, and both can become tame enough to take food from your hands. Personally, i think Leos are easier to care for, but what do i know?
Anyway, if your a beginner when it comes to Herps, then i would say go for the Leopard Gecko. If not, then it is totally up to you. Both lizards can be very rewarding, in their OWN way.
So...
Pros of a Leo-- Easy to care for. Wont get stressed from handling. Becomes tame.
Cons of a Leo-- Nocturnal
Pros of a BD-- Wont get stressed, will learn to love. Becomes tame.
Cons of a BD-- Can be harder to keep (they can become twice as long as a Leo, so bigger cage, etc.)
Now, i dont want it to sound like i dont like either animal, because i give all my pets the same amount of TLC. Like i said before, both can be a rewarding experience if cared for properly.