Best Combo Champ?

I love champs that with 1 combo you can kill a person if you build your stuff right, and personally there is two champs ive tried out with awesome combos. One being Zyra. The fact that you can first root the enemy champion, then place both your seeds on him, Q, and all this while he is still rooted (if your fast enough, which I am). Then your use your ult. Not only will your ult knock them up in the air which in this case my plants have been upgraded by the ult and hitting you rapidly, but when you come back down you are still stunned for about 1 second. And if you think you can get away at this point, the plant still has a good distance to keep hitting you when you run away, and if that isnt enough by Q should be cooled down by now for a final blow if needed.

Next is Swain. Early game around right at level 6 you can easily kill anyone with your nervermove combo.

I tried out Diana, and if she doesn't build AP fast her combo is not that great. its a good support if you plan on ganking with help, but I feel with Diana you can not solo gank anyone except maybe a squishy teemo, and even then Diana is squishy too and can die from teemo. I Q and R fast, W and then E. basic attack while slowed and then Q and R again while they are running. Even then with champs with a good amount of health it still does not do very much of damage.

So anyways what champ do you like that has combos?

Veigar on another AP champion or almost any other semi-squishy champion. Cage dark matter into ult q auto attack combo gg

Jayce can do it very well later into the game vs enemy mids and ADCs.

I like Syndra and Riven.

Malzahar.

Here is a video of me doing some of Zyras combos
http://www.mobafire.com/league-of-legends/video/zyra-mid-recap-of-kill-2163

Brand has some nice combos.

I think one of THE combo champs is Lee Sin. Hit enemy with Q, Q, AA, W, AA, W, E, E and then regain some life back.

So... we're not using all the passive procs we're getting? Weird.

EDIT: We're also not getting full damage off the rotation on a target not moving.
E, AAx2, E, AAx2, W, AAx2, W, AAx2, Q, AA, R, Q, AAx2

Boom, there's a full, max damage combo. It'll be a bit more damage if you kick them into a wall too big to go through. More time for AAs.

Sorcerer's Shoes
Deathfire Grasp
Hextech Gunblade
Abyssal Scepter
Rabadon's Deathcap
Rylai's Crystal Scepter


Buy those on Evelynn. Use R > DFG > GUNBLADE > E > IGNITE > QQQQQQQQQQ
They will be dead after E, but incase they aren't, continue the above.