Maybe I'm just behind the times, but I'm still using a laptop (with XP on it) and when I'm not just reading the comics online, I just use the Windows Picture and Fax Viewer. As long as the pages are in order and in the same folder, it'll flip through them just fine. You can easily adjust the size of the pages if the original size is too small or too big. And it works with zip files, too, although it can't read the .rar files, so those have to be decompressed first.
I've thought a lot about getting a tablet, but I just haven't made that plunge, yet. I'll probably get a low-end e-reader first, and then worry about getting a tablet.