Six Ways Out of Check...

Take the piece giving check.
Block the check.
Move the King.

When your opponent gives check and it repeats the postion 3 times.

When your opponent gives check just as his flag falls.

Your opponent gives check on the 50th move under the no pawn move,
no capture rule.

I'm not allowing SG's illegal move because it will not be recorded in the game score.

Shallow Blue's solution: Kill your opponent.?

I checked the FIDE handbook and it does not say you cannot kill your opponent.
So I guess that is OK as well.

lol

Resign?

Technically, a draw by three-fold or 50-move rule, and a win by time forfeit wouldn't get you out of check. The game would simply end with you in check.

If the above three are okay, then, there would be at least two more ways:

7) A draw was offered and accepted after the checking move was made.

8) A player resigned after the checking move was made.