I'm no connoisseur, but such as I have, I offer.
Like many, for years I smoked mainly latakia mixtures, preferably with high oriental content. A couple of years ago, latakia began to grow distasteful to me, but at the same time, I began to taste VAs like I never had before.
Prior to this, VAs tasted ashy to me. This was partly due to poor form (which some latakia mixtures let you get away with), but also I do feel (perhaps incorrectly, I don't know) that something developed in my palate-brain connection after which I could catch and appreciate the nuances of VA.
In the last month or so, I've been revisiting a buch of latakia mixtures, as my taste for them has partly returned, and I've been curious to see what I still like. I've found that I'm now much picker about latakia mixtures than I used to be -- but a small handful still stand out, and I'm putting them back into rotation.
Still, VAs will continue to be my main thing.
I will confess that I do not get the "lemon" notes from yellow VA that many do. Maybe this too will develop with time, or maybe I'll just never taste that.
Yellow VAs sometimes come closest to still tasting "ashy" for me.
Where I taste the "grassy" notes in yellows most strongly is not in a Straight VA or a VaPer, but actually in a light latakia mixture -- Squadron Leader. There is a little latakia in the background, but to me the dominant note there is freshly mown lawn, from the yellow VAs.
Red VAs have been my favorite for awhile. Notes are sometimes tangy, earthy, sweet-bready, etc. "Tin note" usually has some dark, fermentive fruit (think British figgy pudding), but I haven't found those tin notes to carry over the palate as much as I wish they did.
The best straight Red I've ever had is 40th Anniversary, a gift from
@timt. But that is never coming back, so no point in directing people to that.
Capstan Blue is a very good Red VA, which JimInks tells us hasn't really changed for many decades. It's a few bucks more than many tins, but far less than any unicorn, and readily available. Notes here are sort like a tangy sweet iced tea.
I haven't loved brown VAs so much, although there are many VAs which include them, which I love. HH Pure VA may be the best Straight VA readily available. It's a good price if you buy it by the pound (a very signifant price difference from the tin). It is predominatly Red, but with a good bit of brown and some yellow stacked in there. The flavors are not quite as sweet as some VAs -- more earthy, and very natural and multifaceted.
For dark/stoved VAs, I've been disappointed with Wessex Campaign, which gets rave reviews but always tastes a bit ashy and dark in a quasi-cigarish way to me.
However, Astley's 44 (the other contender for dark/stoved VA) has become one of my all-time favorite tobaccos. I actually taste some of that dark, fermentive fruit in this, along with a good bit of sweetness.
The other dark VA I taste a lot of dark, fermentive fruit in is actually not a Straight VA, but a VaPer -- Salty Dogs. It's expensive -- about twice the price of most 50 g. tins -- and it comes in a very dense plug, so depending on preparation, you probably get fewer smokes from it. It's more of a special occasion smoke for me, but boy, if you want to taste that figgy pudding note, with a touch of molasses or treacle, here it is. Mm.
As others have said, to taste VAs you have to keep them on the verge of going out. They have a narrow taste window -- too cool and they go out, too warm and they get ashy. It's a finicky thing. But if you have the time to relax with it -- who cares?
Well this wound up too wordy. Feel free to bypass!