My hard drive names are pretty generic: Mac OS X and Temporary for the two partiotions on my internal drive; Music and Backup for the partitions on my external drive.
My iMac itself, however, is called Boris (network name). It got it's name from the white hamster my girlfriend had when I got my iMac (in 2002). They were both white and round/fluffy. Well, the hamster was not fat, but it just often sat in a way that made him look like a... ehm... hairball. It was a really sweet animal, by the way. May he rest in peace under on of the big trees in the park.