Online Realtime sites:
BoardSpace - Hive, Qyshinsu, many other abstracts
AsoBrain - Online Setter’s of Catan – with robots and expansions
BrettSpeilWelt - Many many many Eurogames
Yahoo!Games - Chess
Downloadable:
Puerto Rico - (rules) Windows, .NET
Kingsburg - (rules) Java
Can’t stop – (info) Win, Mac, Linux
Citadels - (info) Online java
Catan Dice – (info) Windows, .NET
Acquire – (card) DOS
Plateau – (info) Windows
Puzzles – Various puzzle games available for Android! and most platforms!!
BGG – games with AI
Other Ideas
Palago, Truchet, and others
Online chess bot
Boîte à jeux - En français, Diaballik
X-Earth – desktop screensaver that also shows earthquakes
Pen and Paper
Vector Racer
Daily Fun
Tanga
Problems
Project Euler