I thought you said you didn't want to spend big money. Spiaggia is great (4 stars) but that kind of dinning doesn't come cheap!!! One of my favorite Italian places is Trattoria No. 10 down in the loop. Definately not on the same level as Spiaggia, but very solid food, and a more traditional type feel (being in a below ground level location). I find it to be a little cozier and romantic than Spiaggia.
Another "fun" spot, and surprisingly romantic is Gejas (pronounced gay-has). It is a Fondue restaurant, and is a lot of fun, while still maintaining a nice, quiet, candle-lit atmosphere.
Over, on the edge of where Cabrini Green used to be is Kiki's Bistro. A great Bistro that has been around for a number of years, and has sent many a chef onto bigger and better things (John Hogan used to chef there).
NOrth Pond Cafe has garnered many great reviews (Bruce Sherman was a F&W Top 10 chef), in Lincoln Park, in an older Prairie-style building.
Hope this helps.