local coop games, need ur help!

borderlands

You just missed the borderlands sale :(

Um 2 indie games I can think of are dungeon defenders and sideways new york.

L4D 1 and 2 have mods for local coop if you have 360 controllers. Blur also has local coop.

Gundemonium series and Jamestown, if you're into that. Also Magicka, but you missed the flash sale.

Shank

Serious Sam (1st and 2nd Encounter, SS2 and SS3) have a really nice local co-op. Other games that come to mind are Dungeon Defenders (awesome, but I'm not sure if it's practical on a single screen), Renegade Ops, and then of course hot-seat turn-based games like Worms or Civilization.

All of the deathspank games have local coop iirc, I know The Baconing does for sure.

Overlord. When and if it gets a serious sale.

Renegado ops

Lara Croft and the Guardian of Light is nice, too. It works well in both solo and co-op.

Capsized
Jamestown
hmmm there more but.... I need some time to remember)

Magicka. Great coop campaign and other 2-4 player modes!

Wait for Orcs Must Die 2.

I play a lot of games this way, most of them were already mentioned - another ones: Rock of Ages, Beat Hazard, Audiosurf, there are tutorials on how to play Portal 2 in splitscreen on PC too.

A must have is Bionic Commando Rearmed, hours and hours of fun and it can be very challenging too. Co-op and Deathmatch, local only, gamepads support 4 players.

Gameplay Vid: http://www.youtube.com/watch?v=tL4LL4R754o

Sorry for mentioning games that you already played but here you go ( I havent played them all but they do have local coop, you can check opinions on the steam forums):

all Lego series games, ex. Lego Batman etc.

Trine 1, 2 ( but you mention you finished it )

Lara Croft and the guardians of light - its very very good for local coop

Rayman origins - there is sale for it now during the summer sale

all zombies must die - and similar from the bundle, on sale now as well

the beconin, deathspank, deathspank: thongs of virtue - very similar games, from the same team

gatling gears

magicka

portal 2 ( iirc there is a way to play local coop )

l4d 2 ( same as above )

shank - coop is different than in shank 2

renegade ops

lego batman 2 :3

Shank, Shank 2, Split/Second, Jamestown, Worms.

Dungeon Defenders, Shank, Shank 2, Jamestown, Split Second, Left 4 Dead, Left 4 Dead 2, Trine, Trine 2, and much more but I can't remember them.

I recommend you to take a look at this, listing coach-coop games for PC.
Played with my bro: Obscure, Obscure: The Aftermath, Split Second, Lego's games, Sport's games, LOTR ROTK, All Zombies Must Die!, Shank, Shank 2, Shadowgrounds, Shadowgrounds Survivor, Jamestown, Lara Croft and the Guardian of Light, Shatter.
Looking forward to: Capsized, Renegade Ops, Trine 2, DeathSpank, Bionic Commando: Rearmed.

Hope this helps!

Splinter Cell Conviction

Beat Hazard (I think you'll need a Xbox 360 controller though)

if you count hot-seat, you can play games like worms, heroes of might&magic, civilization and others.

Also-Blur has split-screen for sure.

Portal
Killing Floor

MOBAS : LoL, HoN, Dota2