We're getting a little afield from the Convention Center, but let me put in a word for Farm and Fisherman on Pine Street, which reminded me of several farm-to-table restaurants in Chicago (Nightwood, say); it's a byo (plenty of liquor (state) store options in the area) and it's small, so be sure to reserve.
http://www.thefarmandfishermanbyob.com/Monk's on 16th st is also a good casual, after-work, let-down-your-hair-kind-of-a place to sample some exceptional mussels and Belgian beers, and for a great fish chowder, check out the Oyster House on 1560 Sansome.
Also, if you're around Rittenhouse Sq., visit the original La Colombe on 19th street, and oh yes capogiro as mentioned above. There's one on 20th and one on 13th st. (among others), and it's up there with with some of the best gelati I've ever had, and that includes multiple trips to Italy. (We're not kidding you, it's the best--bring money, tho, it's also perhaps the most expensive).
"The fork with two prongs is in use in northern Europe. In England, they’re armed with a steel trident, a fork with three prongs. In France we have a fork with four prongs; it’s the height of civilization." Eugene Briffault (1846)