havent played 20, but here goes Eclipse - really good port of great space builder game, what twilight imperium could have been, if itvwas bugged down in rules agricola - very good looking port of a game which is almost better without other human players spacehulk - very true too the boardgame, but a bit pricy...
It was Lost Cities. After reading that you like abstract games, you might want to avoid those games I listed. I generally avoid abstract games, so you might be bored by those games I like, and vice versa... Forbidden Island is also good, but it falls into the category of cooperative games, and as explained above, Lost Islands was a typo, or perhaps Forbidden Island and Lost Cities had a very memorable Valentines Day...
I finally found Yggdrasil in the App Store, why was that so difficult? Anyway, favorite board games... Definitely, definitely, Elder Sign but also, Eclipse, Lords of Waterdeep (I really love this one) and Warhammer Quest.
I haven't played enough for a top twenty, but of what if have played (and including card games) - from best to worst: Magic the Gathering (2013 and 2014) (and really I have this on top by a mile) Carcassonne Agricola Ascension Ticket to Ride Monopoly I also have Tigris and Euphrates - but I'm so far from being able to even begin to formulate a strategy forth is game that I find it hard to enjoy it at all.
