I love it. Being able to play literally every console game up until the Wii in 720p... Bliss.
What's the point though? Low res textures, fixed draw distance, usually no Anti-Aliasing, potential slow downs, and sometimes weird graphical issues. I find it best just to play games in their native resolution, windowed mode. That and it allows me to have something playing in VLC or youtube next to it.
I'm pro-emulation, but usually buy old games second hand when I see them. I mostly emulate PSX and N64 games that I'm unable to find. I was so upset when my local game station closed, all those beautiful pre-owned games, GONE.
As I understand it, Emulating games is okay only if you can't purchase it anywhere or own the game AND copy it (make the ROM) yourself. These two both narrow the instances of legal use of roms down very greatly. Most people who use them can't/won't make the roms themselves. While developers may not release all of their old titles for sale, there is a large collectors market for old cartridges and the like. If you can pick up copy of Crystalis in good condition for $70, welp, you're able to purchase it.
However, who's going to pay $70 for an old game? The law may say it's illegal, however, let's look at it this way.
You want game X. X isn't being sold new any more. The Pub/Dev don't get any money if you buy it second-hand. If you buy it second hand the console is going to break eventually. It's unlikely you'll be able to repair or replace it as the consoles get rarer every day as more of them break. Eventually there will be none left.
You might as well just go digital.
I like PC because I can keep my games pretty much forever. At least, the ones without DRM. Oh wait! Cracks! I have some really old games that don't work any more on a modern PC. I play them by emulating MS-DOS. Aren't computers fun?