I stayed in Bonn for about a week to visit some friends. I'd probably never even have THOUGHT about going to Bonn otherwise, but I'm glad I did. As Germany's old capital, it has an active, bustling feel to it. Yet its still relatively quiet and provincial. It's a university town, lots of young people, got that intellectual atmosphere going on. The Rhine runs through the city and there are several picnic spots along the river banks. My friends and I visited several beer gardens with great Rhine views, and there are a couple of really good bars/clubs in the area. Most of the locals go to Cologne though, for serious clubbing and shopping. I personally like Bonn better than Cologne, but then that's just me. Bonn's Marktplatz is charming with lots of eis cafes, street musicians, flower vendors. Public transport is expensive but it's a breeze. There are buses, trams, and U-bahns. Lots of green spaces, and oh, Bonn's claim to fame: Beethoven's birthplace. You can see his house, right in the town center.
As for places to eat, I don't particularly remember names. But I remember a place where we had brunch called Pendel's. Awesome food - gobs and gobs of them, so much so that the table couldn't hold 'em all. Highly recommended brunch place.
Something that drove me crazy though was how EVERYTHING would close on Sundays. Everything. Stores, groceries, bakeries, everything. If you desperately needed something, you had to go to gas stations to buy it at over-inflated prices. And if the gas station didn't have it, then tough, you go to Cologne to buy it. I suppose it is rather refreshing - a non-work-driven pace of life and all - but then it is just something I'm not used to.