what are the simple PC/flash games for seniors?
 

After showing them how to play angry birds, they get addicted to games that they can spend hours playing. Everytime I visit them, they ask for more.

I only have several games so far...Angry birds, gold miner (flash game), Mahjong, Traffic Jam...for sure they cannot handle 3D Sports, RPG and Action games, what else do you think will fit them?

PC is only a P4 1gb ram with onboard video card, so yeah, can't play Halo, battlefield or GTA lol

shockwave.com
addictinggames.com

or just get them a cheapo DS Lite and Brain Age so they won't go demented (assuming they aren't already)

popcapgames.com

Where did you find Mahjong? I can only find those fake Mahjong puzzle games..

Bejeweled 3. Plants vs Zombies. Whatever else is on popcap. They'll probably like the same stuff my wife likes. She's a "casual" gamer, although the hours logged on Steam say otherwise.

My grandma likes bejewled, Zuma/deluxe, PvZ, 7seas, mahjong, Farm Frenzy.
She can spend hours playing these games and the best part is they are very easy to learn/understand.