Why play Tyranids?

So, I'm looking at the tyranids.. And I like the models.. But I havent managed to convince myself to take the plunge and build up an army.. So I decided to ask here, Why play Tyranids? (Other then the awesome models)

Good Airpower, powerful hand to hand, overwhelming your foes in massed waves of gribblies. Quite psychically robust.

I find that having an army that you enjoy painting and enjoy reading the fluff makes for a great reason to play an army. The more reasons you like an army outside of playing the army, the more likely I'm to keep playing them.

I've never been a 'nids fan, but I do enjoy playing against them. Throwing so many bodies at your opponent looks like a fun way to play.

You like the models, what else is there to say?
Every person I know who plays 40k after flipping through rules always ends up playing(very happily too)the fist army that caught their eye. Face it you don't choose your army, the Hive Mind chooses you!
As far as play style(not that I win much), its gonna suck slogging units of 20-30 gaunts across the table top, but hey don't worry, they will be losing aboot 10 models a shooting phase. In fact its almost a mental thing, your opponent will be cheering that the unit is only half strength by the time it gets to combat, but don't worry half a unit will be enough to eat the squishies.
Just make sure to stay in synapse!!!

PS. I am telling everyone I know interested in the hobby to pump the breaks till the new edition is released, I will skip this for you because really, Tyranids can only get better than they are now. A start collecting box and a Tervrigon Brood Primogenitor box should take a bite out of the models you need, nothing like saving some money too.

PSS. They are super easy to paint to, lol