Personally, two tracks I wouldn't mind seeing return, that I don't think anyone's mentioned yet, are Sunset Peninsula and Sedona. Especially Sunset. Sedona was my favorite for drag racing.
Another track worth giving a mention is Positano's much shorter cousin, Amalfi Coast. This track provided some close and fun battles for me back in the day. A section of this track technically returned in FH2, but it wasn't the whole course, just the front straight / tunnel bit. The rest was blocked off by a wall. I was VERY disappointed to find this out when playing FH2 for the first time...