Garen + Cho 'gath

Cho' lays down his ult, hurting them severely, then BAM Garen uses his to finish them!

Karma and any of the following are very strong:
-Jarvan
-Renekton
-Xin Zao
-Lux
-Pantheon
-Amumu

Any melee champion that has a dash, flash, or leap skill and some CC is amazing with Karma.

Taric+Alistar is a super durable push/tower kill combo.. In theory its like Taric+Sion as durable stunners but Alistar can stun more than one target. Also Alistar has his passive which is damage bonus to towers along with his ult then mix in Taric's ult = gg to towers. They both can heal each other to make themselves last even longer in laning and Alistar can heal minions to deny some slower exp for other team. If done correctly, both stuns can be timed for an easy kill or force early blue pill on other team.

Another good combo is Taric+Fiddle, an aggressive lane combo. First Fiddle fears a target then Taric stuns that person while Fiddle is draining their life. If Fiddle is getting attacked, Taric heals him whenever possible.

Me and my friend play a Shaco/ Blitzcrank combo all the time. I lay a box, he pulls them into it, after the fear he then knocks them up, all the while they're getting hit by both of us and the box, and an ignite if even needed. We wreck every other combo we've gone against, and I have multiple SS to prove it. Please consider adding it to the list

Kennen + Vayne. Me and my buddy run this all the time. I stun them, he downs them, or he pins them and I down them. Works great.