I don't know why I'm partial to AKG (I have no connection with Audiophile) ... Sennheiser, AT, and even Behringer all have excellent cans.
My first cans were the AKG 240DF...still have them... still my preferred set. B*tch to drive... so they stay plugged to the board. Flattest cans I've heard.
I also have a pair of Shure E3 IEMs (the gray ones, never released here). These are very decent IEMs. Relatively flat, easy to drive. My favorite travelling set since I got the triple-flange tips from Audiophile. A bit too mid-rangy... but not too bad. I hear the new E4C/G are great but still too pricey for me for a pair of IEMs...still asking sir Tarkuz if they will have AKGs new IEMs... hehehe
AKG K55... I bought these cuz I wanted a pair of closed-back cans for dubbing... and so that anyone can use them... not so painful if someone breaks them. They're ok for the price, although Sennheiser's counterpart at this price range sounds better for me. These feel very light and plasticky.
AKG K81DJ... OMG... BASSSSSSSSSSSSSSSSSS (and I don't mean the honky 100hz kind).... this thing kicks your head in, and the bass is very tight, response is amazing. Mid is slightly scooped (obviously this is for DJs). Supra-aural... 3D rotation for single-ear use. Very easy to drive. These are my most "fun" cans. I also like the fact that it comes with a small carry pouch and they fold up nice and flat. Oddly enough, reviews of it's bigger (and more expensive) brother, the K181DJs aren't as good. I haven't heard them so I can't comment if they are better or worse than my K81DJs. My current favorite... until I get a portable headphone amp for the 240DFs... hehehe. Oh... do NOT use these for mixing or mastering. Just my best guess, it gives about a +6db boost in bass over the 240DFs.
Audio-Technicas sound great too... but I like the build of AKG better. Behringers sound pretty close as well... but feel very brittle. I've never broken one or heard of one breaking... they just "feel" like it while wearing. Doesn't seem to affect their sound quality.