Gurren Lagann for me. It has it's amusing moments but I found it's over-the-top nature not as amusing as my peers. I had a lot of friends who were obsessed with it, but I could just never understand the appeal of it all. I own it and have never had a desire to watch it again after my first foray through the series.

My second choice would be MGS Zeta. Not a bad series per se, but definitely overrated by the fanbase. Not helped by the fact the writing is a bit poor in a lot of places. I never felt like Tomino was terribly great at juggling politics and interpersonal human conflict really well and Zeta shows it as the beginning is rough and hard to follow while Tomino throws in a few redo plot elements like Four who is a shameless expy of Lalah Sue who herself is not exactly the best part of the OG MGS if you ask me. None of which is helped by Kamille being an arrogant and impetuous child for like 80% of the series making him a real drag to watch.