Jack, as always it helps if you start out with a list of what you need from the remote and what you can live without.
If a simple remote trigger is all you need then there are a multitude of them available, I have used Yongnuo ones very successfully and although some of their stuff is pretty bad the triggers I had were rock solid and reliable.
If you want a bit more out of the remote like time-lapse etc then again, there is a broad range and Neuro regularly recommends his hähnel wireless remote trigger which as he says is priced just right if that is the functionality you want.
I specifically need the ability to see the image I just took on the iPad, so for me there are three options that I know of, the work around mentioned before, the CamRanger, and the Canon WFT-E8A. I used to use the WFT's on my 1DS MkIII's but found them unreliable and glitchy, they were also a nightmare to set up with many pages of unintelligible tech speak to navigate to get a connection. The newer WFT's are a bit better and the apps give better options, but it is Canon software and there is a reason they sell cameras and not software! However the WFT does integrate with the camera very nicely and offers weather sealing at an exorbitant price........
The CamRanger and the work around both offer more camera control than the Canon software. I have used pretty much every flavor of remote and have settled on the CamRanger but that is because I have three overwhelming criteria I need filled. I need to view remotely, I need extended bracket sequences, and it needs to just work. If I didn't want the extended control functionality I'd get a WFT.