Sure.
1. (1) Adventures: It balances old and new mechanics, it offers casual and expert players countless hours of fun with Travellers, Events, Reserve cards, Duration cards that are actually interesting (the ones in Seaside aren’t), but also more vanilla cards such as Lost City. Of course, it’s also the expansion that I played the most with IRL, since it came out when my Dominion enthusiasm peaked. To be fair, though, it’s a close call with number 2 on the list.
2. (2) Prosperity: Adventures may be my personal favorite, but Prosperity is more or less the ultimate expansion to Dominion. The Base set offers the basic outline for Dominion, one of the best games ever, but Prosperity is what really puts it over the top. More points, stronger cards, better decks, lots and lots of options.
3. (5) Dominion Base (2nd edition): The Base game was already pretty amazing, but Donald really put the icing on the cake by deleting the six worst cards from it. Probably the best idea in Dominion history after publishing the game in the first place. These days, Dominion doesn’t even need expansions anymore to be a balanced game that can keep someone occupied for years.
4. (7) Empires: I didn’t like a lot of the mechanics at first, but I’ve grown to appreciate them. The Debt mechanic isn’t so bad once you start to understand the rationale behind it, and the split piles offer some interesting player interactions. Of course, the large number of scoring options is the best thing about Empires, and most of the Landmarks are just awesome. The only downside is that most of the Events suck, they’re either too weak or too strong. Empires would have been better without the Events.
5. (3) Guilds: This one remains my favorite small expansion. The mechanics are cool, the cards are pretty amazing, and Herald remains my favorite card to this day. The small size is really its only downside.
6. (-) Nocturne: It still seems a bit on the complicated side with all the extra piles and card rules, and especially IRL I can imagine setting it up takes a lot of time and table space. But online it works just fine and it has a bunch of cool mechanics.
7. (8 ) Cornucopia: Although this expansion lacks a clear identity or anything that really sets it apart (‘diversity’ doesn’t really count), it does contain a number of very cool cards, including Horn of Plenty and Tournament. Yes, Tournament has the player imbalance, but I don’t think it’s such a high-luck card as people claim it is.
8. (4) Dark Ages: It’s a fine set, but it didn’t stand the test of time as well as I thought it would. It used to be one of my favorites but it’s now in the bottom half. I guess it says more about the upper half though. I still like the theme and overall feel.
9. (6) Hinterlands: It’s more or less the ‘little bit of everything’ expansion. It flirted with being another standalone, and I think it would have been better than Intrigue at this role, although frankly Dominion doesn’t need that anymore with such an amazing Base set.
10. (11) Alchemy: It rose two places from the bottom of the list (not counting Nocturne). Honestly Alchemy is pretty hard to rank, some of its individual cards are really awesome and the Potion mechanic is okay, but it does suffer from a couple of design flaws. Possession is just a disaster of course, probably the worst card in existence gameplay-wise, and Transmute is just useless. But then it has amazing stuff like Apothecary, Golem and University on the other side of the spectrum, which is Alchemy’s saving grace.
11. (9) Intrigue (2nd Edition): It’s not a standalone anymore, and for good reason. Intrigue is just not nearly as good as the Base set in my opinion, especially now that the Base set has ditched its useless cards. I played Intrigue before Base, and it’s telling that I liked Dominion, but didn’t love it for the first couple of years. The update didn’t do it wonders either, ditching awesome cards such as Coppersmith and to a lesser extent Saboteur.
12. (10) Seaside: Clearly the worst set. Its Duration cards are bland and unbalanced, its Attacks are highly frustrating and slow the game down by a lot, and it lacks anything cool that sets it apart from the other sets. The only reason ever to buy this would be for completion’s sake.