What is your favorite deck builder and why?

I've been playing a ton of the Star Wars deckbuilder lately and love how the game flows. Want a short game? Play to 3 planets. Longer so you can get a better theme going? Play to 5. I like that it bucks the points to win trend by putting people head to head in combat and that you can attack a lot of things, even the market. Plus it feels thematic.