One thing you guys have yet to discuss, something I'm surprised at, is the actual layout of the engine... the flat 6 sits much lower to the ground overall, which helps keep the center of gravity down. Pretty important if you ask me...

As far as the honda motor goes... one of the best engineered heads in the automotive world, bar none.

OT but somewhat related:
I was debating designing a new flat 6 under 600cc(Inspired by the current turbo motor) so we could run it in a Formula SAE car, but the added weight of spreading the block out and trying to route all that plumbing with a couple of turbos would be a bit tricky... I'm still debating between that or a V8 with a supercharger on it that revs up to 10 grand. This would be a whole lot easier if the car wasn't so darn small!

 

I have a vote for the E-46 M3 engine. I no longer have the car, but it served me well for 5 years and I miss it to this day.

Now I have a 996 GT3 which has the 3rd best sounds emitted from any engine when above 6000 rpm.

My ranking of best sounding engines (not necessarily the best engine):

1. Formula 1 V10 (better sound than the current V8). If anyone has been to an F1 race in person, you know what I'm talking about.

2. Any Ferrari roadcar. They are just so sweet sounding machines with the high pitched revs.

3. GT3 above 6000 RPMs

 

CGT at full song has to be in the list of best-sounding. That was one of the MOST impressive things I saw/heard the first time I went to Crystal Cove.

 

As far as sound goes - CGT FTW!

Still love that F355 Tubi sound though...

http://www.catsspeed.co.jp/test/FR_P...eg_file/05.mpg