And you should use a more descriptive thread title.
Normally, I would agree but in this case...Mac Mini Advice Needed...in the AppleTV and Home Theater thread was pretty much all that I needed to know what I would find once I clicked in here: Advice on what type or size of Mac Mini would be needed for a home theater setup.
Of course, being able to roll-over the title and see what the post was about without clicking would be nice.
Any Mini should be powerful enough, but I second the addition of an external drive.
And be wary that not all iTunes movies are available for rent apparantly...most come to AppleTV first before they are allowed on regular iTunes(?) I have an AppleTV that I view all my rentals on so I don't really know how many rentals I wouldn't be able to see if I viewed exclusively on my Mini (which I use to 'feed' my ATV btw).
I had read here in other threads that many movies have an AppleTV exclusivity when it comes to rentals....this info may or may not be correct...as I said I use ATV so I have none of these issues.