This is one of those questions with no right or wrong answer! Try a site such as:

or a couple of review sites. Most companies make media PCs now, it depends on the setup that fits your needs, in terms of functions (like recording), whether you want a separate screen or use your TV (HP Touchsmart have their own touchscreen), whether you’d use it for other applications and so on.

I am looking to buy one myself soon. What I’ve been doing is just google searching for media pc, or looking at the main PC maker’s websites. Once I’ve found a couple of model names/numbers I search them on google/amazon and look at reviews, specs and prices.

Good luck!