I stole this list from my cousin, hopefully it is accurate and up to date. I know that it will benefit some members here!
Restaurants
Applebee's: 15% off with Golden Apple Card (60+)
Arby's: 10% off (55+)
Ben & Jerry's: 10% off (60+)
Bennigan's: discount varies by location
Bob's Big Boy: discount varies by location (60+)
Boston Market: 10% off (65+)
Burger King: 10% off (60+)
Captain D's Seafood: discount varies on location (62+)
Chick-Fil-A: 10% off or free small drink or coffee (55+)
Chili's: 10% off (55+)
CiCi's Pizza: 10% off (60+)
Culver's: 10% off (60+)
Denny's: 10% off, 20% off for AARP members (55+)
Dunkin' Donuts: 10% off or free coffee (55+)
Einstein's Bagels: 10% off baker's dozen of bagels (60+)
Fuddrucker's: 10% off any senior platter (55+)
Gatti's Pizza: 10% off (60+)
Golden Corral: 10% off (60+)
Hardee's: $0.33 beverages everyday (65+)
IHOP: 10% off (55+)
Jack in the Box: up to 20% off (55+)
KFC: free small drink with any meal (55+)
Krispy Kreme: 10% off (50+)
Long John Silver's: various discounts at participating locations (55+)
McDonald's: discounts on coffee everyday (55+)
Mrs. Fields: 10% off at participating locations (60+)
Shoney's: 10% off
Sonic: 10% off or free beverage (60+)
Steak 'n Shake: 10% off every Monday & Tuesday (50+)
Subway: 10% off (60+)
Sweet Tomatoes 10% off (62+)
Taco Bell: 5% off; free beverages for seniors (65+)
TCBY: 10% off (55+)
Tea Room Cafe: 10% off (50+)
Village Inn: 10% off (60+)
Waffle House: 10% off every Monday (60+)
Wendy's: 10% off (55+)
White Castle: 10% off (62+)
Retail and Apparel
Banana Republic: 10% off (50+)
Bealls: 20% off first Tuesday of each month (50+)
Belk's: 15% off first Tuesday of every month (55+)
Big Lots: 10% off
Bon-Ton Department Stores: 15% off on senior discount days (55+)
C.J. Banks: 10% off every Wednesday (60+)
Clarks: 10% off (62+)
Dress Barn: 10% off (55+)
Goodwill: 10% off one day a week (date varies by location)
Hallmark: 10% off one day a week (date varies by location)
Kmart: 20% off (50+)
Kohl's: 15% off (60+)
Modell's Sporting Goods: 10% off
Rite Aid: 10% off on Tuesdays & 10% off prescriptions
Ross Stores: 10% off every Tuesday (55+)
The Salvation Army Thrift Stores: up to 50% off (55+)
Stein Mart: 20% off red dot/clearance items first Monday of every month (55+)
Grocery
Albertson's: 10% off first Wednesday of each month (55+)
American Discount Stores: 10% off every Monday (50+)
Compare Foods Supermarket: 10% off every Wednesday (60+)
DeCicco Family Markets: 5% off every Wednesday (60+)
Food Lion: 6% off every Monday (60+)
Fry's Supermarket: free Fry's VIP Club Membership & 10% off every Monday (55+)
Great Valu Food Store: 5% off every Tuesday (60+)
Gristedes Supermarket: 10% off every Tuesday (60+)
Harris Teeter: 5% off every Tuesday (60+)
Hy-Vee: 5% off one day a week (date varies by location)
Kroger: 10% off (date varies by location)
Morton Williams Supermarket: 5% off every Tuesday (60+)
The Plant Shed: 10% off every Tuesday (50+)
Publix: 5% off every Wednesday (55+)
Rogers Marketplace: 5% off every Thursday (60+)
Uncle Guiseppe's Marketplace: 5% off (62+)
Travel
Alaska Airlines: 10% off (65+)
Alamo: up to 25% off for AARP members
American Airlines: various discounts for 65 and up (call before booking for discount)
Amtrak: 15% off (62+)
Avis: up to 25% off for AARP members
Best Western: 10% off (55+)
Budget Rental Cars: 10% off; up to 20% off for AARP members (50+)
Cambria Suites: 20%-30% off (60+)
Clarion: 20%-30% off (60+)
Comfort Inn: 20%-30% off (60+)
Comfort Suites: 20%-30% off (60+)
Continental Airlines: no initiation fee for Continental Presidents Club & special fares for select destinations
Dollar Rent-A-Car: 10% off (50+)
Econo Lodge: 20%-30% off (60+)
Enterprise Rent-A-Car: 5% off for AARP members
Greyhound: 5% off (62+)
Hampton Inns & Suites: 10% off when booked 72 hours in advance
Hertz: up t0 25% off for AARP members
Holiday Inn: 10%-30% off depending on location (62+)
Hyatt Hotels: 25%-50% off (62+)
InterContinental Hotels Group: various discounts at all hotels (65+)
Mainstay Suites: 10% off with Mature Traveler's Discount (50+); 20%-30% off (60+)
Marriott Hotels: 15% off (62+)
Motel 6: 10% off (60+)
Myrtle Beach Resort: 10% off (55+)
National Rent-A-Car: up to 30% off for AARP members
Quality Inn: 20%-30% off (60+)
Rodeway Inn: 20%-30% off (60+)
Sleep Inn: 20%-30% off (60+)
Southwest Airlines: various discounts for ages 65 and up (call before booking for discount)
Trailways Transportation System: various discounts for ages 50 and up
United Airlines: various discounts for ages 65 and up (call before booking for discount)
U.S. Airways: various discounts for ages 65 and up (call before booking for discount)
Activities & Entertainment
AMC Theaters: up to 30% off (55+)
Bally Total Fitness: up to $100 off memberships (62+)
Busch Gardens Tampa: $3 off one-day tickets (50+)
Carmike Cinemas: 35% off (65+)
Cinemark/Century Theaters: up to 35% off
U.S. National Parks: $10 lifetime pass; 50% off additional services including camping (62+)
Regal Cinemas: 30% off
Ripley's Believe it or Not: @ off one-day ticket (55+)
SeaWorld Orlando: $3 off one-day tickets (50+)
Cell Phone Discounts
AT&T: Special Senior Nation 200 Plan $29.99/month (65+)
Jitterbug: $10/month cell phone service (50+)
Verizon Wireless: Verizon Nationwide 65 Plus Plan $29.99/month (65+)
Miscellaneous
Great Clips: $3 off hair cuts (60+)
Super Cuts: $2 off haircuts (60+)
Since many senior discounts are not advertised to the public, our advice to men and women over 55 is to ALWAYS ask a sales associate if that store provides a senior discount. That way, you can be sure to get the most bang for you buck.