I own DT 770s (my first true audiophile headphones) and they are extremely awesome. I haven't listened to many other audiophile headphones, but recently went to a friends who bought Ultrasone 550s and some Sony Headphones (cant remember the exact type) and I found the Ultrasone to be similar to the DT 770s in that they produce slightly overemphasised bass (which I love!) but sound slightly more closed then the DT 770s maybe because of the design but I have no clue. I still slightly prefered the DT 770s over the Ultrasone 550s and are supposed to be better then Ultrasones 550s from what I read. The sony headphones were also quite good and were slightly more clear overall but had no real oomph bass which disappointed me as I love things bassy. I think the DT 770 has the overall package as-well.
I was considering the ATH-700 but people recommended me to get the DT 770s and I have never looked back. I am pretty sure you can find DT 770s for $150-ish, as that is how much I picked mine up for ($145 to be exact) but since I live in Australia I had to pay nearly $50 for postage, which is just insane but better then paying $300+ in local stores.
DT 770s I felt were the best headphone I chose for the price, and after listening to its similar competitor the 550s I think I prefer DT 770s more as they feel just like a better quality headphone sound wise. Plus the bass on these bad boys is extreme. Downside is you need to drive the 80 ohms (32 ohms is garbage) or 250 ohms on a PC but they sound pretty good without one (but you can obviously tell the difference between an amp and no amp).
Also these badboys are naturally noise cancelling and use this velvetty valour kind of material I cant describe but it feels extremely comfortable. Only downside was that my head is small and had to wear them for a few hours before they became incredibly comfortable (since I wear them for over 5 hours a day easily).
I would recommend the DT 770s if you can find them for $150 but many other more audiophilic people who are posting have awesome recommendations you should check out!
Good luck in your choice for your father!