I have been a HTPC enthusiast for years. I spent so much time, money and effort trying to build the perfect htpc for all the rooms in my house. What a waste of time!
1) First I started with Microsoft media center.. crashes a lot, interface okay, slow, required frequent rebooting of the computer, lots of drivers/firmware and hardware upgrades.. slow, left me wanting more...
2) Then I ran into SageTV. It is by far the best software, with media extenders which require little electricity and able to play awesome 1080p mkvs files. However, samething, it required a pc (although there is a mac version now), which would require frequent reboots, lots of firmware updates, lots of hardware investment, and the interface is plain fuggly. It is nothing like appletv's interface. In fact, you will NOT find anything like appletvs interface. So I dumped that too. (although if tv, and videos/music/pictures, in ONE box is really that important to you, I recommend Sagetv by far).
3) Still searching for the perfect setup, and being fed up with some shows being recorded or others not being recorded, I ran across TIVO. Yep Tivo. They had just released their new software so that multi room viewing was possible (transferring show from lets say living room to the bedroom),and also it was possible now to transfer shows to the pc/mac to put on your iphone/ipod/dvd. I found this interested so gave it a try. What were the results? The best DVR I have ever had period. I sold all that HTPC junk and have had TIVO for a year now, and couldn't be happier. The only thing is you pay a premium price for what you get.
And what about all the movies/pictures/music? Appletv is THE best media streamer for the price, and functionality I have played with to date. Podcasts, renting high def movies, buying music, viewing movies/music by art.. its the best, and can simply be modified by your itunes on your mac. I do tend to leave my mac on 24 hours, but it isn't necesary, just load up your appletv with what you want then you are done.
So my suggestion after years of playng and wasting money with all that crap, TIVO and appletv in combo.
Thanks
Mo