I like the game where you identify voice actors playing as various characters. Here's what I've got so far:

Pudge - Sniper from TF2
Tinker - Scientist from Half-Life


Also, found a few quotes taken from TF2

Sniper:
Dota 2 - Thanks for standing still, ganker
TF2 - Thanks for standing still, wanker

Riki:
Dota 2 - Cloaked and Daggered
TF2 - One of the Spy's cloaking watches is called the Cloak and Dagger

That's all I can remember off the top of my head. Anyone else find some other references?

for the sniper it is thanks for standing still ganker only if he kill bounty hunter where its wanker for every one else

also tinkers voice is the scientist Dr. Kleiner who appeared in both hl1 and hl2

Lina Puck and Windrunner - Zoey from Left 4 Dead. Lina most noticeable

Wow I knew that sounded familiar nice catch. I had no idea about the rest of these I never played much TF2, that's very cool though.

Some of Tinker's rare quotes are ripped straight from Kliner

Especially the Lamar refrences.

Never fear, Gordon, she's de-beaked and completely harmless. The worst she might do is attempt to couple with your head. Fruitlessly!