Not yet Adam, ( which is a surprise ! ) I briefly tried out " This Is It ", but don't think that's in 5.1 ? I did try out my Toto Blu Ray's briefly, and they sounded great ! ( i suffer from severe M.E. which has worsened, so it's frustrating trying to watch, when my eyes get so heavy. It's easier to just put on music, than watch something, although in the very first few years, i couldn't even get through a cd ! )
do give the MJ History DVD a go when you can Rob. it is surprisingly good. The video quality is v.poor, so you could just switch off the tv and listen to the nice surround mixes instead (just let them roll..)
I do the same with the Billy Joel video collection DVD, just let it play away without watching the video, it has some nice 5.1 on it too.
I use ripped copies of the McCartney years DVDs, just the DTS 5.1 tracks, whenever I feel like giving them a spin, as navigating the original without the TV on is nigh-on impossible - there are some really nice surround mixes on there.
Also the Lennon - Legend Video hits DVD has some great DTS 5.1 mixes, well worth checking out and still nice and cheap and easy to get.