Personally I use, like, and prefer
Altec Lansing speakers w/Subwoofer on the PC because my first set was on my first system that came with them, they left a very good lasting impression; I really like how they are made/manufactured quality-wise when comparing them against rival products in the same price range, and I like the sound they produce again against rival products in the same price range - I'm however not sure how they would fair against Bose speakers though.
Although I have desktop speakers they very rarely get used because most of the time I'm using headphones.