Futurama all the fucking way.
I'll still watch old Simpson episodes, dont get me wrong, but I have to pick and choose which episodes are even worth watching. Simpsons just had a lot of hot and cold episodes all over the place, and not in just recent ones.
Futurama, I can safely watch any episode and expect the same amount or frequency of lols. It's like they have a perfect space of timing to make you laugh, where I watch the Simpsons, and some episodes just drag on forever to build up on one lame or half decent joke.
Anyways, I also enjoy the intelligence of Futurama's humor. I enjoy a lot of their subtle ones too. And the fact that the episode is very versatile between serious and funny, it keeps it interesting enough for me to never get bored. And nevermind the perfect time frame for the show being in the future and what not, which lets them stray extraordinarily far away from the repeating and generic jokes and comedy of the Simpsons or other cartoons today.
It truly was a one of a kind and as much as I wish they continued the cartoons, I'm just scared it'd get tainted anyways.