tanks are often some of the most rewarding, yet least thanked job.. Unless you pick shen, in which case people will notice when you repeatedly save their squishy ass.

However, by the same vein, a tank is often least picked and its less likely someone else will pick the tank role, at least at low elo/levels - many people want to be the carry, because they feel their kd ratio means more than if they win or lose.

Kassadin

Learn to play everyone.

Urgot is unique. Hard to master, since his playstyle is based on punishing enemy mistakes - and for that, you MUST be better than your opponent.

As far as carries goes:
Jax, Tryndamere, Corki, Karthus.

They have some really bad reps, but they are by far the strongest carries in the game. Think of the thing that you hate most about a champ (being literally unkillable, having the longest range AoE while being very spammy, very spammable AoE CCs, having other champion's ultimate as their normal skills, debuffs that literally ruin the game for the entire other team, etc), and these guys will have them.

I've seen a pro Lux once and...omg, its awesome.
Must be really cool to play with. I'm dying to play it and see if it owns that much.

I'm loving Anivia atm, but if your team suck, its really hard to carry. (I know shes not a carry, I'm just saying you can't compensate for your team's suckness as with some other heroes...and this pisses me off a bit. I suppose higher rank games you can't change the tide by yourself anyway, so it's a great hero)

A well played Trynd is quite good too. Phanteon too, really annoying.

Lately Ive been playing Annie since I can kill way more than with Anivia, but long term I guess Anivia is way better

why does no one ever mention veigar in my opion the best solo nuke ingame
has a stun an aoe and crushing ultimate 500 damage (+1) +enemys AP so even when you are weak it is a 1k nuke
and much like pudge in the fact that the longer the game goes the more he grows (AP) with baleful stike giving him the best scaling for a caster in the game
hard to master but when you do you will get scores of 20-2 like i did yesterday

Veigar is a very solid caster,gotta agree with that but he is also fairly squishy and by the time he reaches his full potential everyone in the enemy team got a BV lol,you need to play him with a good initiator like rammus or mumu.