The Muse (*)
There's an a-plot and b-plot to this episode and they both get equal screen-time, so let's deal with them individually.
Jake and the brain vampire: This plot sucks. It's just awful. There's nothing redeeming about it whatsoever, everyone involved in it should be forced to shower in acid to remove any trace of this plot that stuck to them somehow.
Odo and Lwaxana: This plot is pretty meh. There are some nice scenes for these two characters, but the plot itself is contrived. Why must Odo and Lwaxana get married in order to annul the previous marriage? Isn't Lwaxana's unborn child a citizen of the Federation and as such entitled to its protection? Why can't Lwaxana just go back to Betazed and tell her husband to screw himself? I don't know, maybe I'd be more forgiving of this plot if it didn't keep cutting back to the brain vampire stuff every couple of minutes.
Form of... a surface: 26
Form of... an arm blanket: 27