Be aware that, of course, some of the sites sell your info! If you are OK with spam or have a spam email address, then that might work best. Not all are like that, but I always check the reviews before I sign up for anything. I suggest you do the same. All of the below are .com
Totallyfreestuff Website: I like this one because you can actually vote on whether the free time is worthwhile.
Allure magazine has a free sample page: This magazine offers the chance to win free beauty products with a sign up.
Freeflys: A website for free stuff mailed to you.