Hi, Laurie!!! Long time Keurig user here.
First, I would avoid the 2.0 models and stick with the "classic" Keurigs.
I love my K75/Platinum model. You can choose various cup sizes (tiny to travel mug), and the reservoir holds a pretty good supply of water. They're sold EVERYWHERE... Sam's, Costco, Target, JCPenney, Kohls,
Amazon. It's frequently bundled with an assortment of k-cups, too.
I've also used the Mini at work, and given them to my mom and my inlaws. It's good for the occasional user who is okay with pouring water in the machine every time they want to brew a cup:
I would avoid the 2.0 because it uses a scanning technology to identify the pod to decide how to brew. This means it won't work with some of the generic K-cups or the ones you can fill yourself.
I like being able to have a variety of coffees (flavors, decafs, strong brews, breakfast blends) and teas and chocolates for guests and for me. And I LOVE not having to clean a filter basket and wash out a pot of cold coffee every day.