I'd definitely hit up the taste for a couple hours, but if you decide to do that, know where you want to go and what you want to do there, and download the map. Only being here for two days, it'd be a shame to waste it all walking around the taste, even though the taste is great.
As far as restaurants go, there are a million options, and they all depend on what you want. If you want an absolutely incredible, ethereal experience, then it's got to be Alinea or Charlie Trotter's. Coming down a half step from that, but still great, are Tru, Les Nomades, moto, Blackbird, L2O, Graham Elliot, Schwa, Spiaggia, and maybe North Pond. Another step below that is my alma mater mk restaurant, Avec, otom. Then there are a million steakhouses that aren't worth a trip and also a ton of shitty pizza. If you're really into deep dish, my favorite pie is Giordano's, but I'm not a fan of Chicago style pizza in general. And there's a TON of great shitshack kind of food like small mexican places, Hot Doug's, Mr. Beef's, etc.
Lots of options, depending on price and taste and if you're in a rush or just want some quick grub. I imagine that for your anniversary you want at least one pretty nice romantic meal, so if you want some more info on anything just let me know. I'd actually be happy to cook for you but I'm going to be in Florida that entire week.
Edit: OH! And if you are really into great Italian food, go to Riccardo Trattoria. I don't know how I forgot it, but it's the best Italian I've had in the states. I went once with Globe and some guys from the forum and have been back twice b/c it was so good. Great food, nice space, pretty decent prices.