I went through this a few months ago. I use a Mac and there's almost no choice for Mac users. I even put Windows on my Mac - I know, an absolute heresy to other Mac users - so I could access Quiken etc. But because I hate Windows so much I ended up with a dinky little program called ShareManager which utilises the FileManager program on a Mac. It's not online, so you have to enter current prices yourself. But it does calculate CGT and all that. I'm really happy with it. Cost about $280, I think.
