What are the Best IDX providers out there for the money?

[Tom Chambers]

There seems to be an unlimited number of IDX providers for the MLS. A body could lose their mind researching to find out which ones are the best..
There are:
1. IDX content on your site (best)
2. Framed IDX sites
3. IDX off your site
4. Custom Domain Idx sites.
Can anyone with knowledge of all this stuff help me understand which is the best way to go? Lost....
Who has experienced the good, bad and the ugly and would be willing to share your experience.