Best local co-op games on PC

take a look here http://www.steamgifts.com/discussion/5F97B/need-a-good-local-coop

Dungeon Defeders and Castle Crashers!

Yea, you should check that link of Caffettiera. But I'll just copy my answer of that thread in here. If you have questions, just ask:

Hm, depends on what you like. There are a lot of interesting local coop games, like for instance:

• Obscure I (nearly whole game)
• Hammerwatch (whole game)
• Guacamelee (whole game)
• 1001 Spikes (whole game)
• Fistpuncher (whole game)
• Dead Pixels (whole game)
• Adventure of Shuggy (only bonus level)
• Insanely Twisted Shadow Planet (only bonus mode)

Played them all and most of them are really good. But I think Obscure I is one of the best coop experiences I've made.

Spelunky, Broforce, 1001 Spikes, Lethal League, Hammerwatch, and as MorovicFox said Castle Crashers

Lara Croft and the Guardian of Light is so much fun. And the laughs intensifies if you try to do all that timed achievements.

Sanctum 2 is pretty nice co-op.
Torchlight and Divinity Original Sins are also pretty nice.

trine, trine 2, batlleblock theater, legos, rayman legends, rayman origins, gauntlet, magicka, castle crashers, never alone, speed runners, toybox turbo, lara croft temple of osiris, lara croft guardian of light, hammerwatch, spelunky, awesomenauts.

Crawl

any lego game besides what others mentioned

-> Jamestown (if u like shmups)
-> Shank 1* (if u like beat 'em ups)
-> Kane and Lynch: Dead Men (not so great game, but fun when playing campaign with another person)

*- co-op campaign is different from single player campaign (it's a new story)

Lara Croft and the Guardian of Light is one the most fun games I've played co-op.
Borderlands 1/2/pre-sequel is nice as well, but my gf is not really familiar with controlling both sticks on a controller, and I think you have to install a mod for it to properly work on the pc versions.
Resident evil games are nice as well. I think that one or multiple of the FEAR games has Co-op as well, not sure if it's local.
Trine 1 + 2 is nice, maybe shadowgrounds.
Also Pid and Really big sky, but I haven't played those (yet).