I love the monkey. I just don't know which one I enjoy most.
I really love the tailless monkey. The are usually referred to as "apes".
I never thought of them as a tailless monkey. Is that what ape means?
Not necessarily, there are other monkeys that don't have tails but aren't considered apes. The can be distiguished by the motions of the joints in their shoulders. 
How big is the tallest monkey?
I'm not entirely sure on that. But I do know that gorillas weigh more than a lot of other species of monkeys.
Would you know how much they weigh?
Each one varies for sure, but they are the largest type of primate.