From what I've read, Chromebooks with the Tegra K1 are good, but not quite as fast as some of the Intel-powered ones. But one of the advantages of the K1 is that it doesn't require a fan.
Although Chromebooks with 2 GB RAM will be fine for most light-to-moderate work, you should err on the side of getting one with 4 GB, which is notably better if you want to have more than 4 or 5 active tabs open. SSDs are typically 16 GB or 32 GB--unless you plan on saving lots of large videos locally on your Chromebook, I think 16 GB is actually fine (since you'll be using Google Drive more often).
Many people agree that the Toshiba Chromebook 2 is one of the best available right now, mostly because it has one of the best screens. Acer has been in this arena for a while, and tends to make solid devices. I have an HP Chromebook 14, which is high quality. Samsung made the first Chromebooks, but they usually lose points for lackluster performance, due to the Exynos CPU. Asus also seems to get somewhat middling reviews.
One of the great things about Chromebooks is that they're so inexpensive--so it's really hard to make a huge mistake with any of them. Good luck!