Nice was definitely beautiful, especially coming from snowing Norway and a rainy UK but you could probably tackle most of what it has to offer in a day. The people are lovely and there are lots of places to buy cheap but good food and wine (I never paid more than 3€ for wine and never went wrong - thank you France)
Insider Tip:Waynes bar is great if you are young and travelling, especially if you have a few friends with you. They pretty much expect you to dance and stomp on their tables in the back. They also usually have a live band playing.