Category Specific:

Auto Maintenance: Discover Open Road (5% on first $100/mo)
Bookstores: Citi Forward (5 TYP)
Business Services (legal, accounting, etc.): Citi AT&T UBR Visa (3 TYP)
Cable: HH Amex (2x)
Drugstores: Citi Driver's Edge (6% for 1 year, 3% after), Citi Plat Amex (5 TYP for 2 years), HH Amex (2x)
Gas stations: Citi Driver's Edge (6% for 1 year, 3% after), Penfed (5%), Discover Open Road (5% on first $100/mo), Citi Plat Amex (5 TYP for 2 years), Citi AT&T UBR Visa (3 TYP), Costco Amex (3% on $3000/yr), HH Amex (2x)
Internet: HH Amex (2x)
Movie Theaters: Citi Forward (5 TYP)
Movie Rentals: Citi Forward (5 TYP)
Music Stores: Citi Forward (5 TYP)
Office Supplies: Citi AT&T UBR Visa (3 TYP)
Phone Bills: HH Amex (2x)
Restaurants: Citi Forward (5 TYP), Citi Plat Amex (5 TYP for 2 years), Costco Amex (3%)
Satellite TV: HH Amex (2x)
Supermarkets: Citi Driver's Edge (6% for 1 year, 3% after), Citi Plat Amex (5 TYP for 2 years), HH Amex (2x), Penfed (2%)
Travel: Costco Amex (2%)

Everything Else: Citi Plat Amex (3 TYP for 2 years), SPG Amex (1 Starpoint = 1.25 miles*), Penfed (1.25%)

Hotel-Specific:

Starwood: SPG Amex (2x)
Hilton: HH Amex (2x) or HH Amex Surpass (3x)

Airline-Specific:

US Airways: US Airways MC (2x)

Other Brand-Specific:

[b]AT&T[b/]: Citi AT&T UBR Visa (5 TYP)
Six Flags: Six Flags Chase MC (6x)