Well, if Dominion didn't exist, I would spend the same amount of time on the next best thing, which might even better.
Don't get me wrong, I love Dominion, but I don't think it's that exclusive and somebody else might have designed it.
The reason I prefer Dominion is because that's what I was introduced to at the time. If I would have been introduced to Thunderstone or another similar game I might have been a fanboy of one of them and I would be posting this on thunderstonestrategy.com.