5 Paladins will also work really well if you want to go that route. I just stuck with DK's because of death grip for PvP otherwise you'll just have players kiting your team.
For PvE Paladins are just as strong and have some really good utility.

Their DPS is about 40k~ or so on my Paladin at ilvl 468. They have nice passive aoe and good single target.