Which one of these peppers are the least hottest?!

Bannana peppers are much milder than Jalapenos. By "Green Peppers" do you mean "Bell Peppers"? If so they are rated as Zero on the pepper hotness scale. There are a lot of peppers that are Green by the way, including Jalapanos.

Texas gardener who raises several kinds of peppers.

Green peppers, also known as bell peppers, have no heat at all. Banana peppers are moderately hot. Jalape?os can range from no heat (unusual) to very hot, but are usually hotter than banana peppers.

If by green peppers you're talking about bell peppers than those, if you're talking about a serrano or poblano then, the banana peppers are sure the least hottest!

I don't really know about banana peppers, but green peppers are less hotter than jalapeno peppers

edit: when you say green peppers, i assume you were talking about the green chile peppers

Green peppers are the least hot of the three.

Jalapenos without spice... I've been encountering them more and more, so disappointing!

just google 'Scoville scale'