The polar opposite of Ascendancy, the Fluxx take on Star Trek is way less epic, but also has way less setup time. Additional pluses lie in its far fewer pieces to keep track of, and it having basically no learning curve.
You can jump right into Fluxx even with a brand new group of players for fast paced, zany fun with a Star Trek twist. Just about every franchise out there was received the Fluxx treatment already, but if you haven't played before, here's the low down: the rules are constantly changing.
In essence, the changing rules are the game itself, so no two matches are ever the same and a player who seems on the verge of victory is probably the farthest from the finish line.