My opinion: I liked this show a lot, but there are things which bother me.
The things that bothered me were:
1.Boota ex machina (self explanatory I guess =P. He just appeared to save the day outta nowhere)
2. The way nothing ever defeated Gurren Lagann. Not even ONCE
3. Yoko (she just seemed like a generic tsundere-ish character who was there mostly to provide fan service)
4. The show's focus in the first half (from 1st til 16th episode)
Tis' I go in depth with.
So to understand what I mean Gurren Lagann at the base is a story about a boy becoming a man. That boy is obviously Simon. At the very start of that show it did indeed focus on Simon, but soon after Kamina was introduced It all changed. It started to gravitate around Kamina and Simon was eclipsed by him. Kamina was indeed a very entertaining character thus he was the first thing I latched onto. He was the first to act and engage everything and by far overshadowed everything in that show.
I understand why he was set up that way, but sacrificing the focus of the show was not the way to do it. The moment he died this show to me became like a shadow of itself. It felt as if they took the star out of this show. Only 3 episodes after Kamina died the show regained it's focus on Simon again, but it left that little bit of disappointment (also because Kamina was a really entertaining character).
The things that made me like this show were:
1. The mech designs (I like the way they included faces into them. It gave them a bit more of a character. My favorite mech was Spiral King's becos it lookd kewl).
2. Kamina (he became one of my favorite characters of all time pretty quick because he seemed very lively, optimistic and confident and was the focus of the show for quite some time)
3. The world building (it was very interesting and original. It also gave the world this sense of mystery).
4. The way characters progressed in the second half (17th to 27th episodes)
5. The feels, mang.
So yeah. I liked it.
I'm just gonna go to sleep.