It would help to know a price range and what you're using them for as there are a lot of options out there.
For tracking and listening back I use my Sony MDR 7506, but I would never mix on them, they way overhype the lowend. I also replaced the ear pads with Beyerdynamic pads, they're more comfortable and isolating. About $95
A lot of people also like the Beyerdynamics 770s for mixing. I have never mixed on headphones, it always seemed skewed to me, however, some people really like it. These go for over $200.
Under $100 I can't really recommend anything, they usually sound like crap and don't isolate. I also have a few pairs of MoreMe's hanging around for the artists who never seem to get how much wear they put on headphones when yanking them on and off. www.itrstudio.com/moreme.html They don't sound great, but they are cheap and have a great replacement policy.

if you are looking for cheep and good - sony always has a
MDR-100 series for about 10 bucks. usually @ drugs stores..
and booorders.

these are "flat" even the little ones that claim "mega bass"
if they are the light little ones.

Also - I like the sennheiser line of "pro" not the consumer series.

I have the HD250' for 20 years.... and I've had the HD 280s for a couple of years -
and like them just fine.. for $150 or so.

Just know you will want to have a few.

I have used the AKG 250s 20 years ago.... they were good sounding back then

SONY
best bang for your shekels


SENNHEISER 600/650 if money no object