To repeat, as others have said essentially case design and OS system are the key differences. I switched over a year ago to Mac and have a MBP which is a beautiful computer, easily the best I have ever owned.
Having said this, prior to that, I had owned a Sony and a Toshiba, and both were very good; Toshibas are well made and Sony products are very nicely-designed, so in truth, it was more the OS rather than the computers that annoyed me. At work, (I'm in an emphatically Windows working environment at present - so Windows specific that I cannot even access my work emails from my Mac when on leave, though I can from the virtually new Sony which I gave to my brother) I use a HP, which is also a sturdy well-made computer.
Apple also boast an excellent customer service reputation which was another one of the main reasons I switched; two iPods of mine died (battery issues) while within warranty and both were replaced immediately, without seeking refuge in contractual small-print.
Cheers and good luck