What video games are rated A

Do you mean AO? If so, here's a full list (thanks to wikipedia):

• All Nude Cyber (Mac, PC) - Strong Sexual Content
• All Nude Glamour (Mac, PC) - Strong Sexual Content
• All Nude Nikki (Mac, PC) - Strong Sexual Content
• Body Language (DVD) - Strong Sexual Content
• Critical Point (PC) - Strong Sexual Content, Violence
• Crystal Fantasy (Mac, PC) - Strong Sexual Content
• Cyber Photographer (Mac, PC) - Strong Sexual Content
• Fahrenheit: Indigo Prophecy Director's Cut (PC) - Blood, Nudity, Strong Language, Strong Sexual Content, Use of Drugs and Alcohol, Violence
• Grand Theft Auto: San Andreas (PC, PlayStation 2, Xbox) - Originally received an M rating; however, the rating was changed to AO (with the "Nudity" descriptor added) several months following the Hot Coffee controversy. Afterward a newer version (labeled "Special Edition" for the PlayStation 2, re-released as Grand Theft Auto: The Trilogy for Xbox and re-released with a patch nicknamed the "Cold Coffee" patch for the PC) was released on all three systems. These versions had the content removed and are now rated M.
• The Joy of Sex (CD-i) - Strong Sexual Content
• Leisure Suit Larry: Magna Cum Laude Uncut and Uncensored (PC) - Mature Humor, Nudity, Strong Language, Strong Sexual Content, Use of Alcohol
• Lula 3D (PC) - Blood, Nudity, Strong Language, Strong Sexual Content, Violence
• Manhunt 2 (PC) - Blood and Gore, Intense Violence, Strong Language, Strong Sexual Content, Use of Drugs
• Peak Entertainment Casinos (PC) - Gambling
• Playboy Screensaver: The Women of Playboy (Mac) - Mature Sexual Themes
• Playboy: The Mansion -- Private Party expansion (PC) - Nudity, Strong Sexual Content
• Riana Rouge (Mac, PC) - Realistic Blood and Gore, Strong Sexual Content
• Singles: Flirt Up Your Life (PC) - Nudity, Strong Sexual Content (also released in an M-rated version)
• Snow Drop (PC) - Strong Sexual Content
• Thrill Kill (PlayStation) (Cancelled) - Animated Blood and Gore, Animated Violence
• Tokimeki Check in! (PC) - Strong Sexual Content
• Water Closet: The Forbidden Chamber (PC) - Strong Sexual Content
• WET - The Sexy Empire (PC) - Strong Sexual Content
• X-Change (PC) - Strong Sexual Content