I'm also in Nonantum, but the public transportation isn't that great here. I think every village has its pros and cons, but overall I think any village would be great to live in!

I don't know what to say about Newton -- there's so much, but I'll just start talking about it in general and you can ask more specific questions if you'd like.
How old are your kids? The schools here are great, but there has been a large influx of young families in recent years and now the elementary schools are extremely crowded. Most of Newton's elementary schools and some of their middle schools were put on a list of schools that have requested public funds to renovate due to their poor physical condition:
They are (all ES except the 2 middle schools noted): Angier, Bigelow, Burr, Cabot, Carr, Brown (MS), Countryside, Education Center, Day (MS), Franklin, Horace Mann, Ward, Lincoln-Eliot, Mason-Rice, Peirce, Underwood, Zervas
Our mayor David Cohen is an idiot who decided to spend something like 90% of our yearly school budget on a new high school instead of doing basic maintenance on all the elementary schools. He's also paranoid that Turkey is going to declare war on us since we hold a public stance that there was in fact an Armenian genocide. Okay, getting off topic here...
As for public transportation, the villages w/a T stop on the green line are:
Auburndale (Riverside and Woodland are the 2 stops w/large parking lots), Newton Highlands, Waban, Newton Centre, and Chestnut Hill.
In addition, Auburndale, West Newton, and Newtonville also have a commuter rail which runs less frequently (but has less stops and is a much faster commute into South Station).
From parts of Nonantum and Newton Corner, it's possible to walk to the bus terminal at Watertown Square (formerly Watertown Yard) which has express buses leaving for Boston every 6 minutes during rush hour.
For shopping, Newton Centre is the town's major commercial center where most of the town's good restaurants are located. There are also many independent botique shops here. Chestnut Hill area has the 2 malls -- Mall at Chestnut Hill (very upscale) and across the street is The Atrium (where normal folks shop).
In general, North Newton is more densely populated than South Newton because it's closer to the major highways. It's also more affordable to live there. There's 2 high schools -- Newton North HS (NNHS) and Newton South HS (NSHS). NSHS was recently renovated around 2004 and is pretty much done so if your kids are in HS, you'd probably want to look into that area. They are just waiting on a new turf. NNHS just broke ground recently and there's actually a lot of asbestos on the site just across from where the kids are currently taking classes. Parking is also a major problem there.
I think this post turned more into a stream of consciousness thing, sorry. I personally like Newtonville and West Newton because they have some nice amenities and are also in a good commuting location. They're not totally urban, but not totally suburban either.