Since everyone here is obsessed with tomatoes, I suggest a site that has the visitors vote on whether it's a fruit or a vegetable, and then just redirects to a dancing tomato instead of the results.
A website that asks for 4 check boxes to be marked, to progress to the next page (maybe for a million dollars?)
But every time you add the check to the fourth checkbox, one of the other checkboxes unmarks itself. So you click that one, and a different one unmarks. Lol.
A website where you click something that says "see what you get" or "here's what is true about you" and then it gives you one of a handful of affirmations like "you're a good person" "you're worthy of love"
A website where you pick compatible wine or spirit production techniques and it calculates the resulting alcohol and sugar contents so that you can mix and match them but still have some idea of the outcome.
Example
Fermentation - Inputs; water, yeast, fruit pulp (dropdown supported fruit types)
A website that I can go to when I need to provide a profile pic for say, a bot, but I don't actually care about it so I can just grab a random image and call it a day and it'll be funny.
For example my current go to when something wants a profile pic is Walter white's face when he realises he's dying.
So just like, a website that randomly shows 196 images I guess.