If you're into Ennis' Punisher MAX and that dark, deadly serious tone, I'd steer clear of Fraction's Punisher WarJournal or Remender's Franken-Castle. WarJournal (2006) was absolutely horrible - Fraction never understood the character and even admitted it. Franken-Castle would be great as an altenate universe take on the character, but many long-time fans of the character were pretty bitter at the silly idea. In my opinion, it was a good book but not a good Punisher book.
As far as recommendations go, Ennis wrote at least 49 issues of the Punisher under the Marvel Knights imprint from 2000-2004. Rucka's 16 issues Punisher run from 2011-2012 was pretty good too. Also, you can't go wrong with classic Punisher titles, such as the second ongoing (1987-1995), the first WarJournal (1988-1995), and WarZone (1992-1995). Good luck, buddy!