I like the TFL Coralaffix. It is about $9 but it is a huge quantity compares to the little super glue tubes. One tube of this stuff lasted me a really long time and I used it often to glue up my aquascape as well as fragging and gluing down frags. It's perfectly thick. I recently tried the BRS super glue gel, but it's so thick you can barely squeeze it from the tube.

