Dominion is not entirely about "what to buy/gain". It's true a lot of games are like that where you can play your turns on semi-autopilot and only have to think during the buy phase. Luckily, not all games are like that.
Sometimes, during a long turn, you can combine some of the cards in a variety of different and fun ways. Trash for benefits are nice catalysts here especially when they combine with topdeckers, but other such nifty combo's exist.
Did you play a fun combo where you thought: "I'm striking at the core of Dominion here, combining these cards in a beautiful way, it's almost like a symphony." I'm talking about specific (parts of) turns here, not an overall strategy like: "Hey, Ironworks/Gardens is a combo." This is about tactics.
Here's an example of mine to get things going:
— Your turn 12 —
You play a Highway.
... All costs are reduced by $1.
You play a Highway.
... All costs are reduced by $1.
You play a Highway.
... All costs are reduced by $1.
You play a Highway.
... All costs are reduced by $1.
You play a Remake.
... You trash a Menagerie.
... You gain a Highway.
... ... You reveal a Watchtower.
... ... You put the Highway on your deck.
... You trash a Menagerie.
... You gain a Highway.
... ... You reveal a Watchtower.
... ... You put the Highway on your deck.
You play a Watchtower.
... You draw 2 Highways and 2 Woodcutters.
You play a Highway.
... All costs are reduced by $1.
You play a Highway.
... All costs are reduced by $1.
You play a Woodcutter.
... You get +1 buy and +$2.
You play a Woodcutter.
... You get +1 buy and +$2.
You buy a Province.
You buy a Province.
You buy a Province.
So I play a couple of Highways to bring Highways down to $1 and Menageries to $0. I Remake two Menageries into two more Highways and put them on top with Watchtower. Then I use that same Watchtower to draw the Highways along with a couple of Woodcutters. The versatility of Watchtower shows here.
It was a Fishing Village/Watchtower/Library based engine. My opponent didn't have the Watchtower, only a Library. I won't go as far as saying that the Watchtower was the reason I won the game, but being able to both topdeck and draw with it in the same turn is a thing of beauty. I stripped out the FV and Library plays from the log, because they're not that interesting.