Latest annoying/addictive flash game I’ve happened across is this little physics-based stacking thing. You get given a sequence of blocks, and have to drop them in order and make a stack with none falling off the bottom.
Note that when you first go to the site there’s some ad that’s meant to appear, although it wasn’t loading for me. Give it a few seconds of “nothing happening” and a little “skip ad” link will appear to click.
Some of the levels are fiendish as all hell.
There’s a timer on each stage so there might be high scores when you finish the whole thing, or something.