Irelia = Tanky DPS?
 

What build is best for her?

she isn't really a tanky dps, building her as such is neglecting her other abilities

I always saw her as huge amounts of attack speed and maybe some flat ad for the ult...

AD all the way, rush a youmuu's and build a bloodthirster/infinity edge/cleaver/madred's next based on the enemy lineup and items.

I stack AS and that's pretty much the end of it. I've seen her build AP and she failed, and Ive seen her built tank style to great success, but I don't know the tank build. Her W is reason enough to stack AS until ur at 2.0ish IMO.

I usually rush TF with good results most of the time so far. Theres a lot of ways you can build her, just gotta find what works for you.

get 1 hp items just to help her squishyness as of late game

I gear her very tanky.. To be honest I dunno if it's the best way but I basically only stack tank Items, and it works nicely. I still deal decent damage to Carries and I can dive into their whole team headlong with a 63% CC reduction.

My build I have 1v5:ed their team killed their squishiest carry, then ran of.

Like any character than can utilize all of their benefits, I find Banshee's/Triforce extremely effective on Ire. Rush catalyst to help with laning (Q spam is good), then get Trinity and finish Banshee's. She ends up with decent resistances and damage output.

AS and a spirit visage is the way to go for me, sort of a lifesteal tanky dps... but not really.