Whats the best trade you ever made?

My Isaac for COD4 I thought was pretty good. My MW3 for FS Deluxe+Men of War: Vietnam (got a sweet with a preorder for my game that has been on sale). I also got Anno 2070+EYE+Eternia Shards Complete for my Yesterday+Lost Archive (before Anno 2070 sales).

Borderlands GOTY for The Elder Scrolls V: Skyrim

World of Goo key for Alice tradable and Offspring Fling key for Superbrothers tradable and then the two tradables for La Noire Complete.

1x dota 2 for 1 Portal Bundle;
1x dota 2 for 1 AW:AN; and
1x CS:GO + 1x dota 2 for AWCE

SFxT for x8 CS:S

I then traded 3 of the CS:S's for SFxT

Probably CS GO for like 7 Dota2s or CS GO For Max Payne 3 ROW (Preorder 1)

I've had some pretty good trades like Terraria for AC:B, Silent Hill Homecoming for SR3 last year, trine 2 for mw3, dead space 2+ just cause 2 for Valve complete Pack but the one that absolutely blew my mind was a Valve 50% off for 2x Terraria + Magicka

My Portal 2 for 2x Shogun 2 + something else

My CsGo for Darksiders II (tradeable) over three months ago :-)
Best trade (at least for me) ever :-)