As someone who settled easily into the set role of supporting the heck out of a team, she happened to be one of the heroes I grew to like when I took time to have a look at mid lane-associated heroes. She has a naturally built-in positioning with her blink, so you needn't fork out extra money to carry around a dagger, and can therefore throw that moolah into making yourself one kinky mistress. She's pretty decent when it comes to ganking and shutting down SOB's early game, and if nobody's buying wards she can easily dash in and out of lanes from the jungle and nobody would know it was coming until they were a stain on the metaphorical carpet. Her Q is a decent harassing tool, provided you invest in a bottle (or some other early-game regen for your mana pool) and her E and R are wonderful burst damage abilities when it comes to wrecking team fights, or just generally killing off the enemy. I like the way she can dash in and out of fights, generally roam the map and lock down anyone she pleases without so much as a care in the world. The sooner you shut down the enemy carry(s) and such, the sooner teamfighting turns in your favour, and all that.
Granted, my opinion on her is probably
very biased, but I tend to gravitate to the Intelligence heroes, as I often find myself enjoying supporting roles as Keeper of the Light, Dazzle, Visage, Enchantress, Lich, Rubick and occasionally Lion and Crystal Maiden (thought Lion's not my favourite for that kind of role but he is becoming rather popular in that respect). I also enjoy Jungle Chen, Mid Death Prophet and semi-carry Lina/Visage.