Definitely, since I decided to get hexalisted with 10k medals I'm all about medal games. In fact, games with medals are the only games I complete nowadays, feels like I don't have time for any regular (online) games any longer. The more medals; the easier they are to get, the better! But I'm hoping to eventually make my way through all existing medal games on the site... it definately adds to the time I spend on a game, depending on how the achievements are unlocked (IOW if they require you to spend a lot of time on certain aspects of a game). If it's too time-consuming though, and not my kind of game, I'll skip it. Medals with moderation are great.
N1nj4X
I play games because games are awesome. But sometimes, I like to play to get some challenging achievements like "kill 10000 enemies" or "get 1000000 points". Is pretty cool.
Venks
One achievement I enjoy is getting to wins in a row on online ranking matches in Street Fighter. That's something I feel like I can brag about.