Vermintide is a good game, though playing it with friends is a must, as the team AI is a bit dodgy and well, the difficulty of this game is a bit higher than say, Left 4 Dead, if that's your previous experience with these games. It has satisfying first person melee combat though.
If one is to get Warhammer Quest, I recommend getting the Deluxe version, which has all the DLC for a few coins more. The game is a somewhat poorly done mobile platform port, but still plays nicely and is a fun way to kill a few hours reliving the old game.
If looking for a FUN Space Hulk game, don't go with Space Hulk or Deathwing, but instead go with Space Hulk Ascension, which is a polished up version of Space Hulk and plays damn well. Deathwing is a bad shooter that looks good, oozes with atmosphere, but is in the end a disappointment to play. Not even the growls of Toby Longworth could save it for me.
As for Dawn of War 3.. right now it's still too damned expensive for what it offers. While Relic is wheeling out a lot of free content (new skirmish modes and gakloads of reworked / extra skins for your elites), it's too little, too late at this point, as most of the initial playerbase has moved on now. Biggest problems are the micro-management, bland singleplayer campaign (that takes way too long to get to the good stuff) and it predominately being geared towards competitive e-sports styled multiplayer. Yaaaaay...
Funny enough, they pulled the mediocre Warhammer 40,000 Carnage from the Steam store (unless it has been renamed), but kept the horrendously broken Kill Team on sale.