I know there is countless forums with information regarding this topic however, a lot of information is stale or outdated. 

What we are looking to do: We are looking for a list of property owners, their phone number ect. We are focused on Connecticut properties.

So far we have looked thoroughly into List Source and Datatree but not sold on either company.

Please share what sites/companies you have had success with. 

Thank you,

The best source, if you can't gather the MLS in CSV or XLSX format is to go to the county appraisal district and get the list for free. It might take sometime to filters it or you might get lucky if it's the way you need it. But you can get everything you could possibly need at the county if you do it right. Depending on your county it could be a little difficult to parse the many different formats they have. But if you get it right you can have everyone in the entire county (buyers and sellers) up-to-date. Some counties won't have their numbers and if they do they aren't always correct. I have been able to have a significant amount of records across 4 different states.

Listsource is a great option if you would rather just pay now and not have to worry about it. I don't know about Datatree. You would have to use a different service to get numbers. But beware of some companies marketing to your list after you paid for the numbers. Just look around and see what companies would best suit your situation. They can give you 3 to 10 numbers. Some service gives you 3 and others give you up to 10. Hope this helps! Let me know if you have any questions.

@Chris Magma thank you for all that info- I appreciate it. 

@Michael Doherty What you are looking for doesnt exist. If you want a lead list you will have to purchase that list and then pay to have it skiptraced if you want the phone numbers associated with the property owners

@Michael Doherty You should consider working with a list broker who can make suggestions for your market so you aren't mailing to the same people that every other investor found on sites like listsource. 

The broker can also add phone numbers where available to your list in a separate process by running the owner name and mailing address against a national phone and email database (most often whether you got the list from them or not)