I had SS Race mufflers on my e90 and loved em. Pretty loud for just mufflers with no drone at all.
I am currently running a Hartge Rear section, (same as SS Sport) with a catless x pipe and 4 12" resonators and it sounds freaking unreal. Very exotic, high pitched under throttle and VERY LOUD, but absolutely no drone at all. Also, cruising it can be almost silent, but when you get on it, it get's very loud. Running a sport rear section with a catless x pipe it really the best option as it gives you a very loud car when you want it, but also can be very quiet when just cruising w/ no intrusive cabin noise.
Small vid: