So, I stumbled across this new tab site a few months ago and forgot about it until recently. Guitar Tab suffers from the same greatness and tragedy as Wikipedia: it is user submitted. So, you may get a completely accurate assessment of the original song. You may get complete garbage. It can be a pain to sift through the garbage to find the real gems. 

The other major complaint I have had with guitar tab is that it doesn't dictate rhythm. If students bring in Tab it is normally just a bunch of numbers across six lines. This version of tab is only helpful if you are very familiar with the song. With no rhythm indicated there is no way to know how long to hold each note. 

Enter Songsterr. It seems to be more accurate than many tabs I've come across and there is only one tab per song (unlike Ultimate Guitar and others that can have 20+ tabs per song!). This makes it easier to find what you are looking for. 

What I like about Songsterr:
-Mostly Accurate Guitar Tabs
-Guitar Tabs with Rhythm
-Multiple Guitar Parts for each song (electric 1, electric 2, acoustic, bass, etc..)
-Online Lessons available through Tab
-The ability to hear the tab as you read it 

The last one is worth its weight in gold, especially for beginner and intermediate students. If you can hear the tab as you read it (the curser moves through the tab as it is played) it makes it MUCH easier to play. 

Through the free program, you can read any tab and listen to it. If you pay for a subscription to Songsterr Plus ($9/month..cheaper if you buy multiple months) you open up a new world of possibilities including the ability to print, zoom, go full screen, slow down the track, focus mode, solo mode, and looping to work on specific parts. 

Do I recommend Songsterr Plus? There are worse places that you could spend money to help your student succeed. I recommend trying it for a month, and seeing how much it is used. Check it out and let me know what you think!
Songsterr