Upgrading!

So in spite of having held out and promising myself I'd never do it, I finally broke down a couple of years ago and bought myself an e-reader. I wound up with a Nook Simple Touch, and I have been madly in love with it ever since.

Except now it's starting to get a bit old. (Not that old; the original one glitched a little more than a year ago and had to be replaced.) It's running out of battery at random intervals, completely unrelated to how recently it's been charged, and sometimes it's just not responding. Nothing too bad, but it's starting to become a pattern. And I'm left with the thought of what to do.

I love the Simple Touch. What I want, most of all, is a way to read books, and that's all it does, and it does it well. And it's a lot easier for me to read on e-paper than it is on a standard monitor. And it's small enough to fit easily in my purse, and it doesn't weigh a ton.

Except... it doesn't do color. Or pictures. And I'd dearly love the ability to read graphic novels. I just don't know if I want that enough to give up my (slightly) easier reading.

And if I *do* decide to upgrade.... I'm not quite sure what to go with. umbran has a Nook Tablet, and he loves it, but if I am going to upgrade and get a tablet, is the Nook tablet worth it, or should I just bite the bullet and get an actual tablet?

I know bless-all about tech devices; I just know that I like reading, and maybe might want to upgrade my reader. Or maybe not. But I also know that my friends are smart and experienced and more knowledgeable in this field than I am.

So... opinions? What's your favorite e-reader, if you have one? What do you think would suit me best?