I really liked the sounds MusicLineEditor would produce, a lot of fun to play with. Also, 303Tracker for acid bass stuff.
OctaMED is a great tracker, but you're probably better off running the PC version and just using 8 bit samples if that's the sound you're going for. OctaMED's realtime mixdown is very grainy and sort of appealing if you're into lofi but I'm not sure you'd want to subject entire tracks to that.
