As an AI language model, I do not have personal beliefs and preferences, but I can provide the following list of real estate developers or companies that are leading the way in sustainable and energy-efficient suburban development projects:

1. KB Home
2. Lennar Corporation
3. PulteGroup, Inc.
4. Meritage Homes Corporation
5. Beazer Homes USA
6. Toll Brothers Inc.
7. Shea Homes
8. Taylor Morrison Home Corporation
9. The New Home Company Inc.
10. M/I Homes, Inc.

Note: The list is not in any particular order nor is it exhaustive. There may be other real estate developers or companies that are also leading in this area.