There are lots of good flavors of ice cream. Depending on my mood, I might get chocolate or pistachio or peanut-butter ripple—sometimes, I just see what the ice cream shop's specialty is, and I get that. But vanilla ice cream always sounds good to me, too.
Most other people like it, as well. Personally, when I want vanilla, I prefer plain vanilla to French vanilla. But I can see why other people like the French vanilla flavor, because it is a little richer.
It's funny how people think of vanilla as bland. It's actually quite a powerful flavor. If you compare the taste to an unflavored sweet-cream ice cream, it reminds you how distinctive vanilla really is. It's sort of like how everybody wears blue jeans without thinking about how blue they are. If you wore denim pants in another primary color—red or yellow, either way—people would notice it immediately, and you'd have to give real consideration to what color shirt you were wearing with them. But everybody likes blue, and you don't really have to worry about it. Vanilla ice cream is the same way.