Since getting a child I have become a caffeine powered sack of potatoes in a somewhat permanent sleep deficit. The board games I have with even medium complicated rules do not get a lot of playtime.
Luckily I have been able to find some nice abstract board games where the rules can be explained in a few minutes. Easy to learn, hard to master type of games.
NONAGA
The one with red and black pieces and a board made out of small discs.
The goal is to get the pieces in your color to form a single group / cluster.
On your turn move one piece.
It can move in any direction but must move as far as it can.
Then you relocate one disc from the edge of the board.
It must touch at least two other discs.
Kamisado
The one with towers and a colorful board.
The goal is to move one of your towers to the other side of the board.
Towers must move forward, either straight or diagonally.
They can move as far as they want, but must move at least one tile if possible.
The color of the tile you land on decides which tower your opponent must move next.
It does have some extended tournament-style rules where you play several rounds and your pieces upgrade and gain the ability to push. I am sure it adds some depth but for now the simple version is enough for me.
Quoridor
The one with walls. Mine is a homemade oak bootleg version ^^
The goal is to get to the other side of the board.
On your turn you EITHER move one step in an non-blocked orthogonal direction
OR place one piece of wall where it is physically possible.
You are only allowed to place 10 walls and there must be at least one valid path for your opponent at all times.
Quoridor also supports 4 players but it transforms the game from a strategic one into more of a chaotic experience. It's still good fun but it's a whole different experience.