yeah any 2.5inch laptop drive, really for best fit in a standard A1200 case.
and i'll go with the IBM travelstar drives! dead quiet!
s'pose i'm kinda lucky cos i work in support, and when ever someone wants their laptop upgraded i have the old hard disk out and put in another one.
got a few IBM drives 512Mb, 6Gb, and two 12Gb's (one of the 12s is in my 1200

and a couple of fujistu 10-12Gb and a 3Gb hitachi drive. the hitachi drive scared the hell out of me.
power on:-
NREEEEEEEEEEEEEEEEEEEEEE*CHUG**CHUG**CHUG*EEEEEEEEEEEE*CHUG*EEEEE*CHUG*EEEEEEEEEEEEE etc.
never heard anything like it outside of a full height 3.5inch seagate barracuda ultra scsi drive (comes with own cooling fans)
some weird reason tho, maybe its OS3.0, but can only reference the first 8Gb of the disk?