I think my three would be McCoy, Martin, and Johnson.
McCoy has a nice matchup, and has been very productive, so RB1 numbers are fairly likely. Martin is similar; nice matchup, very productive, and no real reason to doubt that he can be successful.
The Flex spot is a bit of a toss-up in my mind between Murray and Johnson, but I went Johnson for two reasons. 1. The strength of his first start. He did extremely well and showed some real talent. 2. The Vikings, whose run defense had been pretty solid earlier in the year, have given up 3 straight games of 100+ yards rushing. That creates some serious potential for mayhem.
Murray isn't a bad backup option. Denver is middle of the road and Murray has been consistent decent but unspectacular. He's the safe pick. Johnson is riskier, but with way more upside I believe.
West, now 3 weeks removed from his three game crazy streak, has a nice matchup, and if there was a time for him to get another big game, this would probably be it, but I'm antsy. It, to me, is a bigger risk than Johnson.
McFadden and Blue have had their consistency issues, like West, but unlike West, they don't have as sweet of matchups, which means they round out the bottom of the crew in my mind.