I've got four of the new Contigo travel mugs with the locking lid. My wife and I have been using them every day for at least six months and we have yet to have one leak. I'm very careful with mine, but my wife tosses hers around like a pillow. Puts it in her document bag while laying on its side. No leaks. Ever. Now, they aren't great at keeping coffee hot, maybe a couple of hours, but they don't leak. Also, the new ones have hinged seals so that they can be thoroughly cleaned (unlike the original ones which were hard to clean and did leak.)
My wife and I are also big Contigo fans. Had one for a couple of years that I bounce around all over and never had it leak. Just this week I bought an upgrade to a 20 oz with the locking button on the lid. Super happy with it and you can pick it up for less than 25 bucks in target.