http://bpfantasy.weebly.com
I'd go with Keenan Allen for sure. He's the #1 WR and should still get plenty of targets compared the other two who are their teams' #3 receiving options. Plus, Allen is used often in the short passing game so even if Peterson hinders his yardage a bit he should have plenty of catches.
Should I start Chargers WR Keenan Allen vs. Patrck Peterson or Ravens WR Steve Smith Sr. vs. Bengals Defense or WR Denarius Moore vs. Jets decimated and beat-up secondary--Im in a PPR League