Cant say i have any great Dark Heresy ones, HOWEVER Deathwatch is a whole other story. My Techmarine Siegfried has had lots o' fun smashing everything in his path, and through his rapid gain of insanity points has become the co-founder of the Deconstruction crew chapter of space marines whose motto is "Crush their homes, you crush their resolve!"
All started when walking into a gutted town, destroyed by chaos marines. As we passed through, two chaos marines with a turret mounted las-cannon atop a ruined building opened fire. Our assault marine, psyker, and apothecary rushed behind cover, however i and my fellow tactical marine rush forward, intending to destroy our targets. more chaos servants jumped from behind rubble and caught the tactical marine unawares, but I bounded on..... to collide bodily with the remaining support structure of the building, servo-arm swinging around madly... the building, and the rather surprised chaos marines, came tumbling down, leaving them all dazed. recovering quickly, i madly take the las-cannon and beat them to death with the butt end of it... the rest of the battle was fierce but standard, save my techmarine brandishing his fancy new club XD