A bit of background reading tells me the 990, as Tarquinh says, is apparently rather good, however, at nearly £1000, that's off the radar for me.  Not so the HK6550, or HK680 from a few years back however.  Apparently superb and very highly rated in their day.  Still actively sought out in some quarters too.  I've also seen a Meridian 551.
Just finding my current set-up is starting to niggle a little; mostly being as neutral as it is (well, I think so), so very revealing with great recordings (a good thing!), but just revealing (read unforgiving) of poorer recordings too.  Hence, I think, why I'm delighted with well mastered discs and it sounds great, but less than overwhelmed with a lot of other material.