For me, all NFSs from 2000 (Need for Speed: Porsche Unleashed) to 2007 (Need for Speed ​​ProStreet) are the best. Well, the first two parts with Shift.
Hmmm... Yes, both are great... I can't choose. They are both the very best NFS, and the last true NFS.
Underground 2 is more relaxed in terms of racing, night city, neon, hydraulics, acoustics and sponsorships with various brands and photos for magazines ...
It feels less speed in it, but car customization is better, there is the same neon, several layers of vinyl, hydraulics and even acoustics in the trunk. Plus free ride, for which you can create a car in the menu to your taste and color and drive it in free mode.
Most Wanted is more focused on action and drive, aggressive racing, chases from the police - the whole point of this game. There are fewer customization options in it, since the game focuses a little on something other than beautiful views and advanced tuning.