If you want s real dark horse, be afraid of the Padres. They are 6 out, but they are clearly the best team of the WC teams other than the Phillies, just look at run differential. They have won 4 in a row, basically they need to almost run the table at this point (no more than 2-3 losses), which of course is very unlikely. If they win 4-5 more in a row they might suddenly become a threat.
Very dark horse, it is probably too late, but if they keep winning they might become a very ugly team to meet in the postseason