Action games
If you don't play games that much, there is a big chance you have played an action game, e.g. a shooter, at some point. This category is full of games that won't let you get bored.
PhinballWizard
Helios and the Spartan
Thing Thing Arena
GunZ 2: The Second Duel
Spiders Arena
Sky Aces 1918
Border Of Insanity 2
Merc Elite
Get the Gun
Fishing Trip
Battletoads
SAGA
MechWarrior Vengeance
The Bard's Tale
Counter Strike Insane Edition
Cock's Revenge
Q9 Action Game
Risen3D
Ninja Man
Marble Arena
Magicka
Kung Fu Panda World Tigress Jump
Nikki the Ninja
Deadhunt
Paladins: Champions of the Realm
Power Instinct
Final Fight Alpha
Full Combat Rebalance 2
DemonStar Secret Missions
FATE The Cursed King
Discover FDM
Add-on support
You can get add-ons that download files/video from arbitrary websites.