If I'm at your average sit-down family restaurant (Chili's, for example), this is my beer pairing most of the time. It's light enough to not fill me up yet flavorful enough to remind me I'm still drinking a beer.
While I think Guinness is overrated, it's still a good beer. However, I don't see how people can pair it with food. It's such a heavy beer, I much prefer to drink it by itself in a bar rather than a restaurant. Maybe coupled with some bar appetizers, if anything.
Mexican food: Negra Modelo if they have it, Dos Equis Amber if they don't.
Cookouts/bbqs/etc: Miller Lite or even High Life. A Mustang Golden Ale or Sierra Nevada Pale Ale if I can get to the liquor store, but most of the time I don't plan that well ahead. Just like pairing Guinness with food, I don't like to pair a heavy beer with hot, outside weather. A good, light, refreshing beer is perfect for those meals out in the hot sun, they quench your thirst while not weighing you down.
Chinese food: Stella or Miller Lite.
Pizza: Stella, Miller Lite, or a Mustang Pale Ale.
Hot Wings: Again, Stella, Miller Lite, or a Mustang Pale Ale. Nothing too heavy.
Once you start getting into the world of stouts and even most porters you realize how watery and tasteless Guinness is. I mean it's the standard for the dry stout style but it feels thin to me now