My list would be a little different RE but I can't argue with Ninja and Imaginos.
Okay seeing we have some momentum, here is the next album 1985's infamous "Club Ninja". This is not anywhere near the quality that fans of BOC had come to expect from the band, no surprise seeing about half the album was recorded with session musicians. The attrition within the group had finally taken it's toll, and from what I've read Blue Oyster Cult considers this their worst record period. There are a couple of good songs, I'll post my favorite and let DKW post his picks.
Here's White Flags, a cover of the song off the Leggat Brothers album "Illuminations".(I like the original better, but this version is okay.)
Here's the cover and despite the average contents I thought this was one of the better covers BOC had over the years.