Though I haven't played it for decades, I'd have to say that five card draw is probably my favorite because of the memories it carries. It is the first game that my parents taught me when I was a "tween", and I had many enjoyable hours playing it with my friends from work in "dealer's choice" games. Not knowing at all what your opponent might hold also makes it, in my opinion, the most exciting of all the games. I totally adore Texas Hold'em that I play in tournaments, but my first love will always be five card draw.
The hardest thing about being a trans-woman is trying to learn how to not enjoy The Three Stooges. I've failed miserably. LOL!!