Hmm.... This is just my opinion. But it really depends on what you are looking for. And how well you are will be confortable with. Android for me is the best OS out there because of being an open source and always having update. Maniacattact is right. Apple they just wants money.

Im already happy with my N900. But if i ever going to have a alternative OS i will go to android. And carriers would be HTC because of build quality.

We'll just have to wait on what will Meego will bring on to the table.
Hope this helps.