I would just like to chime in for anyone who's interested in brainstorming, and say that a fruit is pretty much anything with seeds. (That's the reason both tomatoes and peppers are fruits despite not seeming like it.)

Apparently also with Andy Murray's fingers.

Which is why technically the pizza base is a fruit.

I tend to be one of the pedantic ones explaining what is/isn't a fruit etc.... but I think when the subject is not about the science it's probably best to stick to the common definitions (even if they are not so precisely defined). That being fruits are sweet/sour and vegetables are not (at least in uncooked form they are normally a bitter flavour).

So I retract my mention of peppers & olives, but raisins/sultanas are definitely fruit.

Pineapple is the only one.

Delicious. Though I'm much more interested in Roger Federer's expression

Is pepperoni a fruit?

Tomato fo show! (with veggies like Spinach and Broccoli) 

Figs on pizza tastes good.

Pineapple on pizza is sublime.

I suppose tomatoes count as fruits botanically...though I always call them veggies. Can't think of any other traditional fruits that might work. Maybe mandarin oranges?

Tomato