I like them both, in terms of how they work and their lore/aesthetics, but which one should I get? I'll probably get the other one at a latter point in time, but I can't decide on which one is better/which one to get now.
Rumble for damage during teamfights, Maokai for cc and peeling.
Maokai has a much wider variety of playstyles and builds. You can go full tank, AP bruiser, Mage, Support. He's a ton of fun with a solid kit and balanced well so you can use off-builds without too much trouble.
maokai imo is about as boring as watching grass grow, I like rumbles play style of being an overall prick in lane and have game changing potential [:
