Paragon is fantastic. I own a whole wall of early Ballys (and a couple Williams) and Paragon is probably my favorite. It can be brutal, but so fun. And being a widebody, there are so many different things to shoot for / ways to play. Sometimes I start a multi-player game and play each player with a different strategy. Not all games from this era have that many things going on.

If you like Black Knight, you should also think about Solar Fire. Always felt it was the best of the Williams double playfield games.