In this rainy weather we are currently experiencing in California, I am really enjoying the boardgame: "RAF: The Battle of Britain 1940" by Decision Games.
I have had little experience with "solitaire" games. RAF contains two; a game for the RAF player and another for the Luftwaffe. It also has a two-player game. So you are getting three games in one. I have just tried out the RAF solitaire game "Lion" and find it is very enjoyable and highly playable. It really works as a true solitaire game.
How it does so is via a very sophisticated set of cards designed to simulate raid targets, dates and times, sizes and formations. Really thrilling and highly recommended!
Here is a link to the game page:
As usual, Boardgame Geek has numerous useful aids, reviews and demonstrations of the system. I found the game through Geek, learned to play it and how to order it. What a service to the gaming community!