Well, if you don't plan on getting a headphone amp, I'm going to have to retract my recommendation on the super.fi 3. The impedence is far too low (13 ohms) to use without an amp/line out combination, and you will experience an unbearable hissing. Atleast out of my 5G video, the headphone out is unbearable. The included impedence adapter fixes the problem, but it's not worth the effort if you can avoid it.
As for the fit, it just seems to depend on your ear, either they fit or they don't. Personally, with the silicone smalls inserted, the isolation is amazing, and I have no problems with fit. Using the reverse mod also furthers the isolation, while adding to the form factor. Also, the sound remains virtually unchanged, unlike the mod on the super.fi 5.
I agree with the other posters, definitely you should check out the Mylarone X3's...and the Atrio's can be had for $130 + shipping on ebay, also a great value. The shures I would avoid, but I've heard good things about the Jays.