Here are a few free sample sites that I have visited & what type of offers I found.
ScamFreeSamples - lists several free samples without surveys. Many of the free samples do arrive by mail while others are in store only. This site lists printable coupons & other special deals on-line, giveaways, contests & sweepstakes too.
FreeSamples.org - lists a mixture of free stuff without surveys, with surveys, in the mail and not. While sifting through their listing I have found some very fine free samples as well as other offers I wouldn't have tried.
SampleADay - lists a mixture of free samples with and without surveys and other requirements and a lot of the samples arrive in the mail.
Several years ago we asked ourselves a similar question as yours. We asked "Where can we find completely free samples, no surveys and nothing to buy?" We came up short. So we decided to make our own:
Sampleloft - is a user friendly listing of completely free samples, without surveys & nothing to buy. This is the only type that we list. There are times that we list free samples that are in the form of a printable coupon that visitors can bring to the store but this is far and few and in between. Some of the free samples listed may ask 3 or 4 questions but I don't classify that as a survey. Questions like: "What type of shampoo do you currently use?" Multiple answers. Even this is rare.
We also decided to create a free sample site review & rate it web site.
FreeBeeBuzz - Currently we write our visitor experience review, provide a link for fellow free samplers to visit the site reviewed & then rate it. Visitors can meet even more free sample sites here and perhaps find a favorite. We even list our own free sample web site there because we want real ratings from real visitors.
Free sampling can be frustrating but it can be fun & thrifty too! I hope this helps. Happy Sampling!