I'm not a massive fan of the e60 M5. I love the engine but the gearbox and weight ruin it for me. After a month or two you do begin to get along with the box more but its more about learning t olive with it than loving it.
For me it just burns a lot of fuel and is a big big car. I feel an M3 gets more more fun with less cost and a better look. Not as nice inside but everything else suits me better.
I would go an M3 over an e60 any day but everyone's different.
On another note my Feb build car has just landed in Aus if people are wondering how long it takes. I guess its time for a thread soon.....