Please suggest a <50$ gamepad for occasional PC gaming / Steam Big Picture

Yeah, I'm actually going to have to say PS3 controller (which I'm using) over the Xbox360, because of the Dpad.

One thing I've learned about reviews commenting on build quality is that very often the people who complain that something broke were completely mistreating their stuff in the first place. Throwing their controller around, stepping on it, forcing things when they shouldn't, etc. As for the adjustable tension, yes the actual adjustment... things are kind of tricky to operate without feeling like you're going to break the damn thing, and I haven't had my onza for a long time, but I'm personally confident in its build quality. There is also the option of getting the non-TE version which shouldn't have that particular problem.

P.S. the programmable shoulder buttons are fucking amazing. Goes a long way towards making some tasks in games so much easier, like inventory management in Dark Souls.

P.P.S. There's of course no wireless, and the cord is fucking loooooooong.

I own 2 F510 and 1 F310 and I can confidently say that they are awesome

I've had my 310 for several months now. I wish I had a longer time of ownership to go off of, but I've had no problems out of it, though it hasn't been subjected to heavy use the entire time. I take care of it, don't drop it or the like, but I'm pretty rough with the left stick in particular, generally, during use, and it's held up fine.

Durability was one of my main criteria when I purchased it. Based on reviews, the only problem I saw mentioned more than once, I think, was the occasional unit having the wire go loose and losing connection where it connects to the controller, and it may be the only problem I saw given at all. I assume it's a common defect from imperfect manufacturing processes and occurs at a predictable rate. A new one is likely to be under warranty if you encounter it, or you can do like I did and pick up a refurbished model for $15, free shipping, and be assured everything is in perfect working condition.

From what I gather, the XBox 360 controller is probably the best you can get, but cost and the fact I don't care for the left stick/pad layout means I went with this, and from what I've seen and experienced, I'd say it's probably your best bet for a PS-style controller for PC.

Edit: It also has a switch on the back for toggling between DirectInput and XInput, so you don't need any other software or anything for games that want an XBox controller.