Should I buy Saints Row?

I've played GTA for a quite some time. I really enjoy the gameplay and I heard Saints Row has similar gameplay. Thus, my first thought was whether or not I should buy Saints Row, and which title I should buy. I'd like information about each Saints Row title in the series, a brief comparison of the games and which one you would recommend to me. Thanks in advance.

Edit: I bought Saints Row 2, 3, and 4. I don't know which one I'll play first, but I no longer need help with buying, so replying to this post is not necessary.