I know many of us are very familiar with Line and Row/Crisscross/Tateyoko/ whatever you call it. However, I often find it ends up being the same students answering because they are strategic about what they choose, or they get sick of it. So heres some variations.
Adding diagonals. Self explanatory, I usually add these as soon as the students are used to just line and row to liven things up.
Make the kids ask you questions instead. Maybe this is obvious to some of you, but it took me quite a while to think of it. I say something like make a sentence using indirect questions (間接疑問文）
Dice
Write an option for each dice number on the board, eg 1- line, 2- right hand diagonal, 3- only you etc. Once they answer the question, they roll the dice to see who sits down. The advantage here is that the game will go a bit longer, plus it changes which kids may have to answer. Another plus is that you outsmart the pesky classes who all choose row so they can finish as soon as possible.Potentially infinite- if they choose a row that already has people sitting down, those people then stand up.