I picked up a pair of DT235s a few months back and have been more than happy every since. Now that I've easily got a few hundred hours using them they sound fantastic for the price. Enough highs without being annoying, decent mids and enough bass without it feeling like there's a 15in sub strapped to my head.
I bought the DT231 recently (good price) and use them a lot, perhaps now my favourite headphone. They are an "easy listen" and suit a wide range of music and I've had more episode of just "drifting off" with music since I got them. In fact even at home when I'll often use them instead of my best headphones (Alessandro MS1) just because the are so welcoming and in general don't need a lot of fiddling with EQ etc to sound good but they do respond to a little bit of amping which is however more probably due to the signal coming via the line out than the headphone needing amped as such. I get the impression I'd need to spend quite a bit to find a significant step up from these headphones. They are a little bit anonymous in the looks department though if thats important to you.