What....

Anime should i watch!?!?!

Now to make it IB here is something about flying cars!

Meh, that car looks like bird turd. I'd rather have a gangsta ass jetpack.

i like the skycar better

You should watch all 3.
And since they have as much in common as ... eee ... things that have very little in common, I can hardly advise on the 'best' one without knowing your preference.

Shakugan no Shana for a romance filled with action and tsundere loli.
Black lagoon for the action gun theme.
It all depends on what themes do u prefer.

Go watch Sword Art Online.

Initial D of course