Off the top of my head there were three main suits and one or two casual outfits.
The suits: opening film/Zhora chase scene suit (the most well known shirt and brown pants), visit to Tyrell to test Rachel with the Voight-Kampff and final Bradbury/Roy Batty chase sequence with the orange looking herringbone pants and jacket. Up until recently the final suit was near impossible to get accurate shirt pattern references for. When the final shirt went up for auction the pattern was very interesting to see.
Casual outfits: Rachel love scene ( I think maybe a dressing gown from memory) and the strange knitted thing he wears at the end for the final visit to see Rachel.