Originally Posted by mayhem13
Please don't as your requirement of reliability isn't met by HTPC's.
This wasn't one of the original requirements, but I know for me this is a big consideration. If the OP is handy at working on the HTPC, then it is not an issue.
I have a couple ATVs (both version 1 & 2), all jailbroken and I have no issue with streaming DVD rip movies. I have experienced the stutter with a couple Blu-ray rips, so that was a pain. I have installed XBMC on the ATV2, but have not been successful in getting it configured to access the movies on my NAS.
Overall, I am very happy with the ATV2. There is almost NO issue with playing files, movies or music. PLUS, the ease of use is a BIG factor for me since the wife and kids also have to use it.
I did make the mistake of watching XBMC on a Mac mini and was VERY impressed. This combination is a FAR better solution then the ATV2, but it also costs $500 more than the ATV2. The only "mistake" is now I want this setup. The difference between the two is like the difference between eating a steak at a local diner or at a steak house. They will both fill you up, but if you can afford it, the steak house will provide a MUCH better meal.
You can use iTunes on the Mac mini for music or go all out and use JRiver Media Center. On the video side XBMC is an excellent option and only getting better. The form factor of the Mac mini is very nice since it is so small and quiet, and the power draw is very low.
Sorry, forgot to mention the web browsing. This should be considered a given since the Mac mini has full browser capabilities.