I guess I'm lucky because I take 502 to/from work everyday. 502 has a section between LA and the turnoff for Espanola that is steep uphill and has 3 lanes up / 2 lanes down. It's super fun to attack the uphill section at faster than traffic speed, especially since 3 lanes ensures you can pass if you need to.
Hwy 4 has a really awesome twisty section between Bandelier National Monument and the Valles Caldera - lots of really tight 20mph twisty turns. Traffic is usually light, but there are a lot of bikers near Bandelier in the summer so going fast there is not a good idea. Between Bandelier and Valles though... fun fun fun.