I can recommend you two very good restaurants in Wroclaw:
There's an Italian one "La Scala" in Rynek (Market Square) and next to the Rynek you can find another Square - Plac Solny - filled with many florist's opened night and day.. non-stop. There's the other one - "Akropolis", where Greek food is served.
Both are a bit more expensive than the other ones, but in my opinion they're the best :)
I've heard about a good Japanese sushi bar - sakana.pl, but never eaten there.
One more thing.. If you're going to visit Wroclaw you have to step into the Spiż brewery in the Rynek as well. It has an incredible atmosphere and they always serve the beer with some berad and lard (smalec). That's a perfect combination :)
Ahh.. I'm getting hungry :)