I just found out I can get either one for my high school graduation. Now I can't decide.

get the m5 i have a 5 series sport and would love a go in the m5

If it were me I'd go M5 all the way. But I'm 28 years old and your what? 17,18? Be sensable and save mom and pop a couple bucks. Get a 2007 Infiniti G35s. It's sporty and it will still make a statement.

Wow, you are one lucky kid! I personally, absolutely love the 6 series, but the M5 is definately sportier. Since your only about 18, I'd go with the M5, I think the 6 is more for older people like me.

I like the BMW 6 series better than BMW M5.

your definatly very lucky both are nice cars but the m5 is a lot better it is a lot more sportier faster better looking and more expensive you can sell a m5 and get two 6 series with that money and the 6 series is nice but its like a apartment comppared to a 100 milion dollar house

BMW 6 Series :

The 2008 6 Series is a 2-door, 4-passenger luxury sports car, or convertible sports car, available in two trims, the 650i Coupe and the 650i Convertible.

Upon introduction, the 650i Coupe is equipped with a standard 4.8-liter, V8, 360-horsepower engine that achieves 15-mpg in the city and 22-mpg on the highway. The 650i Convertible is equipped with a standard 4.8-liter, V8, 360-horsepower engine that achieves 14-mpg in the city and 21-mpg on the highway. A 6-speed manual transmission with overdrive is standard on both trims, and a 6-speed automatic transmission with overdrive is optional.

The 2008 6 Series is freshened for 2008.