1. Bubblegum Crisis: Tokyo 2040. Consider this if you will: it's the year 2040, and robot servants and labor workers are all the rage. However, the robots tend to go into berserk mode for no reason and the only way to stop them is Iron Man. And by "Iron Man", I actually mean four women in wearable battle armor suits who call themselves the Knight Sabers. I cannot recommend this series enough. Hey, there's even a belly massage scene in one of the episodes ... and some full frontal nudity later on. Yes, it's a remake of the 1980's Bubblegum Crisis, but I liked this version much better, especially because it has a (mostly) satisfying ending.
2. Cowboy Bebop. Because no Top 5 list would be complete without it. The series just had "cool" written all over it. A jazzy space opera, with a ton of pop culture references/homages, and lots of creativity behind it. Plus, Faye Valentine's bare belly ... and also Ed's, although that might make you feel guilty sometimes.
3. Voltron: Defender of the Universe. Yep, because I'm old school like that. This was my gateway drug into anime. I didn't know it was anime until decades later, but it was first anime I ever watched. It is the reason why to this very day, I love all things related to giant robots. Oh, and there's that one episode where the team goes swimming and we get to see Princess Allura in a bikini.
4. Full Metal Panic: Fumoffu. My favorite comedic anime. You kinda have to watch the original Full Metal Panic series first in order to know who all these characters are, but the sight gags are still funny to watch without knowing who everyone is and why what they do and how they act are so funny. And like all anime, there's the token beach episode and token hot springs episode, just as an excuse to get everyone in bikinis or semi-naked. Oh, and you'll never look at amusement park mascots the same way ever again after watching this series.
5. Sol Bianca/Sol Bianca: The Legacy. Okay, this one takes some explaining. The first Sol Bianca was made around 1991/1992, and was only two episodes long because it ran out of production money. Then in 1999, a six part mini-series was made, which had the same premise, but not the same storylines as the original. Unfortunately, neither version of the anime has a satisfying ending. As for the subject matter, it's the tale of five female space pirates, and their misadventures as they travel around the universe in search of treasure and Earth relics. They're armed with everything from laser whips, to a laser sniper rifle that can fire from low orbit, to landmate mech suits, to a spaceship that can teleport and destroy an entire fleet in one blast. Just good old fashion space opera fun.
Honorable Mention: Aeon Flux. Pretty much the coolest thing ever to air on MTV during the 90s, the golden era of that network. It's not quite "anime", but it's close enough. I think it deserves a modern remake. Oh, and course that's the infamous "The Purge" episode, which NEEDS to be made into a live action adaptation. I don't care who makes it or who stars in it (although Rachele Brooke Smith tops my list), but it NEEDS to be made!