Spiaggia is nice, but I have to admit, I always feel like I overpaid after eating there. As I recall, the entree price is around $30-50 and in general I end up at around $150/person after alcohol, appetizer, entree, dessert. The tasting menu is nice there are well (~80-120/person depending on the day and the menu). View is nice, especially if you are by the window, atmosphere: the room is actually quite well lit, noise level: sedate, very classy decor.

For romantic Italian, I also like Trattoria #10 which is at 10 N. Dearborn. The room is darker, the crowd tends to be theater goers and the like. Slightly less expensive than Spiaggia (~50-75/person I'd guess) Also nice and quiet so it is easy to talk.

If money is no object, Tru is considered to be one of the best places to go. Haven't been there myself, but my friends who have gone rave about it.

If view is more your thing, then Everest is for you. The food is great, the view is beautiful from the 40th floor. Be aware that it is also very expensive. Haven't been there in almost 2 years, so I don't have recent prices, but trust me, if price is an issue, this will blow your budget.

Just for the record, Bin 36 is also great, and it is one of my favorite lunch spots, but at night it tends to be VERY noisy, so you may find yourself straining to hear your date.