I liked Torchlight and I completed it. Torchlight is a lot like Diablo with Warcraft style graphics. It definitely has a Blizzard feel to it.
My main gripes with it is the lack of multiplayer (even LAN would be nice) and every zone seems to be underground. At least Diablo had outdoor zones and you'd enter caves/dungeons and such.
As for Borderlands, I'm still in the starting area and about to move on, the loot is similar to Diablo and the way everything spills on the ground. Borderlands is a FPS with "quests", levels and loot and is focused on ranged combat.
I'm guessing you probably won't like it. Did you like Hellgate London? It's very similar to that game.
I didn't vote because the 2 choices were