I'd say the Acer C720 is still the best value. The latest model with the i3 processor will give you the best performance, but the original C720 with the Haswell Celeron 2955U processor (which is what I have) is totally fine. The 11.6" size is highly portable. I don't think the touchscreen is worth paying extra for--I personally find it awkward to go from keyboard to screen to keyboard. The screen is pretty mediocre, and the build certainly doesn't feel premium, but it's pretty solid, and it's hard to beat for around $200. Besides, you can always get a cool skin (I just got a burlwood skin from Decalgirl.com--it's totally sweet).
If you want a bigger screen, the HP Chromebook 14 (which I also have) is a good value, and can be found for a little over $200 refurbished from various sellers. It has the same decent Haswell processor. If you find one with the T-Mobile 4G data, then you have the added safety net of 200 MB/month of free T-Mobile 4G data (regardless of what wireless provider you already use). The Toshiba Chromebook 2, with a 13" screen, also sounds very promising, and hopefully has better build than their first one.