I think that Shaco is the hardest to use due to the fact that it is almost mandatory that you jungle with him to be effective and he is very different from other junglers. Akali is a lot of fun, but its hard to get started without runes. Kat can be done without runes and is a lot of fun, but gets shut down by hard CC.

Katarina is fun, Akali is rough.
But what do I know.. I'm just a Kat fanboy, lol.

imo akali isn't very fun because i find her very easy.. i don't like easy champions.. same with kat

also i like to go solo, AKA i dont mind not having a laning partner or someone following me around

Kinda depens on how you like to play, Akali is an insane burst-caster, and pretty much devours even build-completed squishies. However, she's not useful to pushing lanes and unless you really coordinate your kills with team offensives, you'll be contributing nothing to your team. This is especially true in normal games where I've seen Akali get over 15 kills with zero deaths on the losing team... more than once.

Kat really isn't a ganker. She can fake it with a Rylai, but despite the looks, she's a caster. She can be built well to push lanes, or hop in after initiation to do terrible, terrible damage.

Shaco is similar to Akali, in that he can absolutely eat squishies, but he's more about positioning, ambushes and baiting than OMGBURST. Unlike Kat and Akali, he also has the advantage of being able to take out towers pretty well. He's also a pretty popular pick in 3v3 if that's your style.

I'm torn between the too, don't get shaco though.

Akali is definately a single target focus assassin, but kat is mana less nuker who can be really fun if your team has a brain and knows how to focus people down. I love them both, so get them both!

ok maybee im confused on the definition of gank, i use it in the term of ambushing to take out an opponent or two what is the real definition

Shaco, get shaco and own

As said earlier, Akali is too rune dependent to play at level 18.

Kat is ok but I'm not a huge fan.

I would choose Shaco. He and Nidalee IMO are both the highest learning curve and the most fun characters. That said hes good to start learning early. You will probably loose alot at first but once you have him down hes one of the best in the game.

Akali and Shaco are extremely dependent on you ability to know when to enter a fight in the late game. Your positioning, entry and proper use of cooldowns (it is not always correct to Deceive in or Twilight Shroud the moment after your Shadow Dance) will determine whether you live to chase down and kill runners or explode.

Kat doesn't really die if she Shunpo's in at the wrong time, she just either gets her ult off properly or she doesn't.