Well, I get in free, so I guess I have to go.
Living Greyhawk is the biggest RPG at DragonCon, although there are still other just plain RPGA games too. In those, you are given a character.
There is also board gaming, miniatures, and LARPing.
Things to do in the city itself are not that important, because there is way too much going on to leave the con. 20,000 people are a lot in one place, and people watching can by itself be a full-time activity.
I try to go to the High museum of art every few years. You will want to go to the Varsity and get a chilli dog, but be ready to order or no soup for you!
There are lots of, umm, dance clubs nearby to see, umm, dancers...
Downtown has a lot of one-way streets, so it can be difficult to get around to the hotels. You might want a map.
Eating is okay, there is a Wendy's and the very expensive hotel restaurant. Nearby is a good sushi bar if you like eating bait. But not too many restaurants. There is a mall/eating away in the elevated walkway, but it closes too early and is not open on the weekend.
That's about it. Try to catch one of the bands there, they have some pretty unusual things there from time to time, my favorite was a tribal drums band with near-naked dancers...
