1st generation NFS = the PSX/PS One & PC titles from the 90s/early 2000s.
Hypothetically, we could also include Hot Pursuit 2, but I won't include it for practical reasons.
The Underground, Most Wanted, Pro Street, Shift & Undercover games = *not* 1st generation NFS titles by any means.
- The Need For Speed (1994; 3DO, Saturn, PSX, PC)
- Need For Speed II (1997; PSX, PC)
- Need For Speed III: Hot Pursuit (1998; PSX, PC)
- Need For Speed: Road Challenge/High Stakes ("NFS4", 1999; PSX, PC)
- Need For Speed: Porsche Unleashed/2000 (2000; PSX, PC)
My fave = Porsche Unleashed with TNFS SE on 2nd place. (note that PC version of Porsche is much better than the PS one; the PC one should have been ported over to PS2)
High Stakes was not shabby either and Hot Pursuit genuinelly impressed me when it came out, graphically. (PC version)