Of course there are a bunch of ways to build a team but the DH's only job is to hit. So you want the best hitter you can find to fill that role.
2011 Posada sucked. There are tons of guys who will be reasonably attainable who can hit better than .290/.330/.390.
Freddie Freeman, Cody Ross, Angel Pagan, Chris Johnson, Justin Morneau, Allen Craig, Alex Rios, Adam Laroche, Cory Hart, Jason Kubel, Chris Davis, Alfonso Soriano, Paul Goldschmidt, the list goes on. Not all of those guys will still be hitting like they did in 2012 in 2015, but other guys will. All these guys have league average-ish OBPs (~.330) and SLG in the mid to high .400's.