Like CFH said Sep 19 is Mayweather/ Marquez

But there are plenty of others:

Juan Diaz/ Malignaggi is on Aug 22nd, Robert Guerrero/ Malcolm Klassen is on the undercard I think

Over here we have Tua/ Cameron on Oct 3rd

Carl Froch/ Andre Dirrell on Oct 17

Chad Dawson/ Glen Johnson 2 on Nov 7th

Valuev/ Haye on also on Nov 7th

Cotto/ Pacquiao on Nov 14

Kessler/ Andre Ward on Nov 21st

Bute/ Andrade 2 on Nov 28th

Plus there's a heap of other entertaining fights in between but I think those are the big ones...