Any good "windowed" games?

Desktop dungeons

That

Game Dev Tycoon

Gridiron, and Faerie Solitaire.

Super Smash Flash 2, if you like the Super Smash Bros. Series

The Binding of Isaac

minesweeper, minecraft, vvvvvv, cogs, various indie puzzle games, super meat boy,

Read the title as "widowed games", twice. Perhaps those topics on "dead games" make me think in a weird way :(

Gunpoint maybe.

super meat boy

FTL
Super Hexagon
Hero Siege

Binding of Isaac, Super Hex, Little Inferno, Scribblenauts.

Civilization V

And hearthstone

Civilization V

And hearthstone

Defender's Quest: Valley of the forgotten.

I have a special category "windowed" for games I play when my computer does some time-expensive operations and I have to keep an eye one them and I always have sth like that installed.
I used to play Open TTD and Battle for Wesnoth a lot.
Right now I'm playing Steel Panthers 1 on desktop and Lure of the Temptress on laptop. I was playing UFO Defense but it sucked me in too much and I was losing focus on work. In the next batch I have prepared are M.A.X., Prisoner of Ice and I Have No Mouth And I Must Scream. All of the games mentioned in this paragraph are DOSBox titles.

FTL

One Finger Death Punch :3

last knight, broken sword 1-2

grindy MMO's

FTL, Cthulhu Saves the World + Breath of Death VII

Peggle, Peggle Nights, Bejeweled 3, Plants vs. Zombies, and others PopCap games

Both English Country Tune and Splice worked really well for me. They're both pure puzzle though, so it's most certainly not for everybody.