Playing Torchlight just makes me want to start up Diablo II again.  The loot/farming aspect of the game just isn't there.

I bought it back when it was on sale. Diablo was so much better. Barely worth the $2.50 (?) that I paid.

Try some of the mods for torchlight. 
There are a couple that alter the game a lot and may help you with your treadmill addiction.

Played and beat Torchlight recently.  Installed D2 last night.  It's a much deeper game.  Don't know why I would continue to play TL over D2.  It's also got a lot more bugs and ambiguous mechanics.  There's also the familiarity I have with Diablo.  Why learn a new system, when I already possess so much nearly useless knowledge about Diablo.  Also, multiplayer.
 
Edit:  Ah yes, now I remember, achievements.  The saving grace.

Nope, never mind about achievements, started up D2 and I'm hooked again.  I can see me playing this for several weeks exclusively at least.

I could totally see myself getting hooked on D2 again if I started it.  However, I am on a mission to play all the good games I missed from my WOW days.

Same here, I couldn't get pass the Jungle-ish level. Made me want to play a game similar to Diablo 2 but couldn't find any so I went back to Diablo 2 spicing it up with the Median XL mod.