Here's where things get crazy.

There are a lot of OP champs... You just don't know about them.

First on the list, Swain.

While he is not a force to be reckoned with on his own, he brings great team fight potential with his ult keeping him alive and harming the three closest enemies. Combined with the ever-popular Will of the Ancients and the not-so-popular Spirit Visage, he can live through some of the most brutal team fights. Early on in the lane, a combo of Torment, Nevermove, Decrepify, Ignite can leave most lane opponents either dead or running for their life. Throw in a strong jungler gank from the snare off of Nevermove and you've got a guaranteed kill!

Coming in at strong second, Ryze!

Reason's why he's so strong? Q, main skill, 1-2 second CD. His skills, when used in rotation, make his other skills cooldown faster. Strong AoE and free spell vamp at or after level 6 along with skills that scale off of mana means you're not going to be leaving lane for quite a while. With an MR reduction, it makes him brutal in 1v1 fights and a pretty fierce team fighter. Again, with a snare, he becomes a powerful mid lane champ that can get kills pretty easily with the jungler's help. The fact that it's an on-demand, ranged, unfailable snare means kills or a forced flash are almost ensured.

Moving on, Maokai.

I'm probably going to kick myself for this but, Maokai is an amazing champion. Like Ryze, a ranged snare. This one however is also an initiate. Using this skill is basically saying to your team, "**** yea! LET'S DO THIS!!!" Combined with your ult, which you can keep at level 1 if you don't use it for damage and team fights aren't happening often, and you will not suffer much. Saplings act as free, damaging wards when/if you lane him and the havoc he causes in the jungle is amazing with his on demand root and slow/knockback.

Now that you've read to here, you might as well pick up one or more of the champs. Strong solo queue presence who can carry games if the lane goes right. Maokai can practically carry from the jungle as well.

Basically, I'm saying buy these champs.