One problem is that "what is best" depends on your needs.
For some, it's all about cost. For others, quality or convenience. And just like cell phone service, sometimes it just depends on where you live...
For example, the Obi PhonePower service is interesting to me except that you can't manual provision and can't easily change Caller-ID spoofing, so it's a no go for me.
Final example: a number of people have had issues forwarding GV to a Vestalink DID, but for me, it's been working really well (no noticeable added delay).
I really do like my little Obi 202 box; even after dumping GV, for less than the cost of Ooma Pro, I'm getting more features and more redundancy.