EOS Remote with 70D
I only reluctantly got a 70D because of video (new grandchildren) even though I loved my 7D, it couldn't focus during video and children move a lot. I thought the wifi and EOS remote were gimmicks that I wouldn't use a lot.
Well I was wrong. I really like the EOS remote. I find that I am way more likely to change my perspective to be low or high, since the remote opens that possibility up. Of course you could do simillar with the same with live view and a cable release. But with the remote you can easily change the key setting on the camera, the focus point etc. I'm really loving the capability and didn't see that one coming.