The curb weights are always debated but here's the numbers from a single source:
E30 M3 Coupe curb weight: 2645 lbs, 192 HP, 13.77 lb/hp
E36 M3 Coupe curb weight: 3439 lbs, 240 HP, 14.33 lb/hp
E46 M3 Coupe curb weight: 3399 lbs, 333 HP, 10.18 lb/hp
E92 M3 Coupe curb weight: 3648 lbs, 414 HP, 8.81 lb/hp
http://gearpatrol.com/2014/07/21/history-of-the-bmw-m3/
Personally I love my E46 330. Similar power to an E36 M3, better interior, half the cost. I'd have loved an E36 M3 to tune up like Mike has, but my goals were a bit different.