The plotline is broken down into four segments:
Segment 1: Lala is here - everyone go crazy (underlying tone throughout)
Segment 2: Suitors from other planets - everyone goes crazy.
Segment 3: Everyone is in love with the hero, Rito - still, everyone goes crazy.
Segment 4: Quest to become #1 in the universe - Everyone (mostly Rito) goes crazy
These segments are fun and would be enjoyable to watch, if the show were 12 episodes long. However, when these segments are stretched out into 3, 4, or even 5 back-to-back (sometimes broken up by an episode) episodes with a similar theme, it's going to get predictable and boring.
The characters are what pull this show out of the dumpster. "To Love Ru" decided to go with the "million shades of gray" character personality list. You got your introverts, extroverts, flirts, perverts, control freaks, etc., etc.; all types of character are represented here and each are given a good amount of screen time so that they become familiar and likable.
I loved the opening theme to the series. I usually tend to skip the opening themes to most animes because it's always keeping me from getting to the actual content. "Ru"'s, however, won me over. The catchy up-beat tone and truncated guitar chords, coupled with the change in octaves and tempo of the voice always made me feel like I was hearing it for the first time, every time. The best opening theme I've encountered so far.
Being that I can't really compare how the art style translated to the anime from the manga - I'll let that comparison slide - but I really dug the art style that was employed with "Ru." That classic anime feel that is has to it - almost old school - but clean and crisp enough that you know it's part of a newer era of anime.
I liked this anime. I liked the amount of fanservice, I liked the amount of romance. I just can't get past the typical harem ending we find ourselves in again. They try to distract you, it seems, by (attempting) to pull off an ending that is so ludicrous and "WTF-ish" that you almost forget that, all-in-all, it's a harem.
Story: 6/10. Nothing anyone hasn't already seen, heard, thought already
Art: 9/10. A classic anime art style that's clean and crisp.
Sound: 10/10. Apart from the amazing theme, the voice work is good. But, c'mon, that theme kicks ass.
Character: 8/10. Would've liked to have seen more of the main female protagonists' feelings. Enticing and enjoyable characters, however.
Enjoyment/Overall: 7/10. A good anime for a viewer that doesn't mind harem endings. I do, though, and the score suffered because of it.
