Wheezy to Jessie can't select DE @ login
 

Was using xfce4, updated to testing and when update was done things were alittle buggy so I rebooted, when I logged in I went straight into gnome. Tried to log out and switch but didn't get the drop down. I rem and reinstalled and I still don't have the option, any ideas?

Try this:
Boot,
Click on your username
Now click of the gear next to the Sign In button.
That should allow you to select your DE.
But I find I like gnome 3, once I discovered the gnome shell extensions!