King of the Hill G10:
Win 100 games of Klondike, Spider, or FreeCell
If you've already done this on WP8, play one game of Solitaire and this will pop.
This is for completing 100 of one of those games, not cumulative. 100 games of Klondike counts, 40/30/30 doesn't. Also, daily challenges do not count as games. Thanks ShadyShall for the clarification.
In terms of consistently fast games, I would rate Klondike on Deal 1 as the fastest, followed by Freecell and Spider on One Suit being equally slow. Spider on One Suit can be done quickly, but this is the consistently longest game, so unless you've been playing Spider for a while, it's not a good option. Similarly, Freecell can be confusing, and games can last anywhere from 3-8 minutes.
Previously the fastest way to do this was FreeCell, but with an update, choosing a specific deal no longer works. I've left the old solution intact in the spoiler tag below in case anyone's interested.
Under Game Options, change the game to #10913. This is the fastest game to beat, and even taking time with the solution, it can be done in 1:30. With repetition, it can be done much faster. Solution is below which only takes into account your own moves.
First character is the card value, second is the suit. T is Ten.
01) 5D -> 6S
02) 4C -> 5D
03) TC -> JH
04) 8S -> 9H
05) 9D -> Freecell
06) JH -> Empty Column
07) 7D -> 8S
08) 6S -> 7D
09) 6D -> Freecell
10) 6H -> 7S
11) 5S -> 6H
12) 4H -> Foundation
13) 5H -> Foundation
14) 4D -> 5S
15) 8H -> 9S
16) QH -> Empty Column
17) KC -> Freecell
18) QC -> Freecell
19) 9S -> Foundation