Here in MT, about all we can get is clover or alfalfa honey; both of which are fairly nondescript honey varieties. Not bad, just generically honey flavored. They're great for melomels or metheglins, when you want the fruit or spice to shine & the honey to be in more of a support role.
I do like orange blossom quite a bit & mesquite is a nice honey too, with just a wee hint of smokiness, but I think my current fav has to be acacia honey. It's so floral & delicate, best in a dry or semi dry mead IMHO. The trick is in retaining those delicate floral aromas through fermentation. It's twice the price (or more) of the clover & difficult to come by, so I've only made 2 small batches with acacia honey, but they were quite tasty.
Buckwheat honey is very dark & strongly flavored, some liken it to molasses, though I've always thought it had a sort of "barnyard" or dry hay and/or hay tea flavor to it; it's not for everyone. It's so strongly flavored that it's usually used with another variety like clover to lessen the intensity of the buckwheat flavor in a mead. It seems to be one of those things that people either love or hate, with little in between.
In short, I use the mild, generic honeys for melomels & metheglins and the distinct varietals for straight meads.
Regards, GF.