I would say Xbox 360 is #1 with relative ease, once you subtract the RRoD issue that will never be rated over time and if you were to discount PCs induction
To date: best games library[opinion], best media options[unquestionable], and best online service[unquestionable] and probably the most innovative console of all time considering previous generation options
I would rank the systems as follows
1. Xbox 360
2. SuperNES
3. Playstation 2
4. NES
5. Playstation
6. Playstation 3
7. Nintendo 64
8. Xbox
9. Dreamcast
10. GameCube
11. Wii
12. Sega Master System
Etc etc
but it's really hard to gauge... 20 years from now, when live is down for 360 - the opinion may change... Digital content is dependent entirely on connectivity... And we are discussing this in the present generation- I have a hard time playing PSX, N64 games now so I'm seemingly placing them in the list due to how good they were in their time
The bar of quality and level of acceptance keeps evolving, what I perceive as quality today may not be considered good later
If I were to list consoles due to their importance, i would probably put the 360 in fourth, behind NES, SuperNES and Playstation
PS2/GameCube/Xbox/DC generation was the most evolutionary generation of all (outside of rather short but fun leap between DC multiplayer and Xbox Live) and I think the generation after this might be the worst generation yet...
evolutionary, media taking over gaming, cookie cutter games
As much as I think Xbox 360 pushed console gaming forward... I think that it's eventually going to hurt more than its going to help in the long run