Ok. I can't be bothered to make a YouTube video, so you can just read.
First of all, Windows Media Centre. If anyone starts thinking "...but what about FrontRow", I'll rip your head off, shove my hand down the gaping hole and pull out your spleen. FrontRow has absolutely nothing on Media Centre, it is a merely a fancy front end for Apple's existing programmes (read if you don't believe me).
I'm going to be talking about Vista Media Centre here.
First of all, photos.
All of them are organised nicely, tagged of course - which it can take from Windows Live Photo Gallery, Windows Photo Gallery or Windows Media Player. You can also view it by folders. The slideshow button is available everywhere, to which you can play music along with.
Which brings us to music.
There are a multitude of ways you can display your music collection.

(Albums by Year and Now Playing page)
Ok. So on to TV. It is simply the best PVR software out there. No competition.
As soon as you start watching TV it starts recording, so you can rewind straight away, pause, etc. without waiting for the timeshift to kick in (and missing out on that important bit). It can handle Dolby Digital (2 channel and 5 channel - but no 2 channel matrixed sound (ie. Dolby Pro-Logic II/IIx)) as well as HD TV (1080i). The TV guide works without a hitch (in America anyway, a bit of fiddling is required in Australia), and will record your shows and organise them by series and episode. Another great thing, it works with Zune! You can have all of your TV shows on it! It's brilliant.
Another thing (which I won't go into too much detail, but you can Google it), you can extend this entire experience to your TV (including the PVR stuff) even if your PC isn't next to your TV - through an extender, like the Xbox 360. What's great is, say you are watching a show on the main TV, and decide to go to bed you can continue watching it in bed without watching a beat - mid-show.
The menu fades in very nicely over live TV or video, and if you are at your computer using it - move the mouse over the window and controls pop up for you.

(Menu overlay and control overlay)
Anyway, I have to go now - if you want to try it, get Vista Home Premium or Ultimate (x86 or x64). It's great.
Let's see your Mac do that.