I like Athena Solitaire. I enjoy playing it and it isn't too difficult. The rules are identical to Klondike.
Subjectively it appears easier than Klondike. You can see the values of some of the cards on the Tableau, with the added frisson of not knowning what is hidden behind every card. This makes it more interesting:)
Each Column only having a length of four also helps. You have more opportunities to manipulate place the Kings (or so it appears to me).
Athena, Klondike (one card deal), Klondike (three card deal), Minerva, Munger, Mystique