I'd definitely go with "caster decides destination" for teleport and similar spells (which includes long door and leaving). For leaping, I say it just allows the target to leap (it doesn't move the target), so target gets to choose destination (where to leap). However, since these spells are U spell, only willing target can be affected, of course.
I CAN see a few scenarios where the question of "Umm, sure, I'm willing to be teleported to A, but not B" would come to question. Then I think one of two would apply. Either:
A) You either accept to be teleported and take your chances, or you DON'T accept to be teleported, or
B) You claim that you're willing to be teleported to A, but not B, so if the caster tries to teleport you to B, you're not a willing target, and nothing happens.
I have to think about which one I prefer, but right now, I'm leaning towards A. Similar problems applies for other U spells as well, I'd think.