I for one thought the Plants in archive were amazing. =]
It definitely made me chuckle especially the mattress that it was accompanied by, haha. Gotta be comfy for the occasion of course.
As for easter eggs I've only found that plant, Sharpsh00tah's signature in runway and the L33T room in archives. I had a question about that... I noclipped into it and was able to open up the door in the wall from inside but not from outside in... I tried both sides. Is it even possible to get inside that room without noclipping, if not, why is that wall openable at all? =P
I've been very curious about this, I've wanted to do surprise attacks from the L33T room. xD