last year there werent any mid range cards... only low end and high end...
The 8600 is the low end from last year...
You would want a mid range from this year (which performs on par with the high end from last year)...
The only cards worth buying right now are the:
3850
3870
8800GT (256MB and 512MB versions)
Dell has the lowest prices on these, and they are all in stock... but due to Christmas it will take 1-2 weeks to ship.