Sennheiser is a decent company and most of what they put out is decent. I've seen 201s at very low prices. ebay has some store demos for sale for around $25 including shipping. They're only 30 bucks new from Sennheiser, so I'd shop around. I'm not sure if you are near any audio stores, but giving them a listen first is the best idea. I auditioned my hd497s before I bought them, although they also let me listen to some HD600s which were drop dead wonderful. Both are open ear headphones, though.
http://www.ebay.com/itm/Sennheiser-HD201-Lightweight-Over-Ear-Binaural-Headphones-/221242542051?pt=US_Headphones&hash=item33831547e3 Eh. It's only c. 15 bucks. Live a little. Give em a try if you can get em for that price. I picked up better models for about 25 and am waiting for them to arrive.
The Sennheiser site is another place to get useful info about the available models. Unless you get them for at least half off, I'd buy them from Sennheiser or an authorized reseller so you get the 2 year warranty. I contacted them when my hd497s had problems with the earpads disintegrating and while they were discontinued, they offered me another comparable pair at half off, not much of a deal. I later called them again and found replacement pads and a new wire that were very easy to replace for less than $20 so I went with that option.
I'd stay away from stuff that is mass produced or cheap unless you know people who've used them or can listen yourself. I hear beats by Dr. Dres are overpriced, for example. Sony can produce good ones, as can skull candy, but you have to be selective and do research. Grados are well regarded, but every model is different. I'm by no means an expert. I just tend to get sort of obsessive when I buy stuff and do lots of research first. It's been a while since I've been shopping but I haven't needed much.
That said, if you can come across some good bluetooth for cell phone or decent earbuds or small portable headphones that I can carry with iPad, I'd be happy for any suggestions.