In love with the #68k "Address Register Indirect with Postincrement" addressing mode. Yes, I know we have every fancy thing imaginable today, but thinking about it in context, I think it's amazing.
.loop:
move.l (a0)+,(a1)+
dbra d0,.loop
Where d0 contains the number of longwords to copy. Address increment works with words and bytes as well? Love it! #assembly