Bubblegum Crisis I remember rather fondly. I will probably watch it again. Heh actually that was on my "to do" list for awhile. Tekkaman Blade is indeed a good one. It was right before I graduated highschool when that aired. Not the best of them out there, but still very good nonetheless.
Mazinger was one of the first I had ever watched. It was tranzor Z when it had aired. I think I was 7 or 8 years old at the time I watched it. I see that there is a whole universe for it, and I think I will put that on my "to do" list as well. I always wanted to follow that one further than I was able to. I will check out Zambot-3 as well.
I had heard some good things about Lone Wolf and Cub. Being that it is a Seinen, I will definitely be checking this one out. Someone in another thread suggested brave 10. I might look into that one. It sounds like it may be too Naruto-like though.,
These suggestions are good, sometimes it is good to revisit the classics and older animes too. Some I had long forgotten about and have fond memories of.
I am glad of you find my recommendations interesting.
So that you watched the -severaly cut and watered down- version of Mazinger when you were a kid? That is cool.
Well, if you want to check it, let me give you a tips:
Firstly, it is a series made for children and young teens. So keep in mind that.
Secondly, even though many people thinks (wrongly, IMO) that 70s mecha series were nothing but monster-of-the-week, plotless, light-hearted shows, the Go Nagai original manga was pretty dark. It also switched magazines during publishing, so that there are two tankobon compilations, and both have missing and arranged-out-of-order chapters. And some compilations published the final of the series in the first volume of the sequel (Great Mazinger). So you see, it is somewhat chaotic, although manageable. The anime adaptation is softer and lighter, but it changes the characters personalities (Kouji became a sexist jerk, Sayaka became more violent and angrier...), and it drags on after a while (it was supposed to be fifty-seven episodes-long, but it was lengthened due to the succes of the series). Some episodes are nothing but "Bad guys send another robot and good guys think of a tactic to destroy it", whereas others twisted the formule, advanced the plot or added more personal conflicts (believe it or not, some episodes dealt with bullying, parental abandonment...).
There are also another manga version because the editorial realized that two Mazinger mangas would bring more sales than a single one. It is written by Gosaku Ota and it kind of it is a manga adaptation of the anime. You do not need reading it, but it is noteworthy because it elaborated upon the motivations of the bad guys and gave them a backstory.
Great Mazinger and Grendizer are the sequels. Both have two manga versions -the original manga written by Go Nagai and the Ota version-. It is better watching the Grendizer anime because the Go Nagai manga only... stops. On the other hand, the Gosaku Ota manga ends... in an apocalyptical "let's kill almost everybody" fashion.
New Mazinger -or Mazinwarrior-, Mazin Saga, Z-Mazinger, Mazinkaiser, Shin Mazinger... are alternate stories, reimaginations or reboots. Shin Mazinger Zero is kind of another sequel, since Kouji is stuck into a time loop. The first chapters are pretty dark (honestly, it was like reading a blend of the original manga and End of Evangelion).
Moving on...
Dirty Pair is a hilarious sci-fi series, starred by two intergalactic crime solvers that tend to accidentally blew everything up as they are trying to solve a case. Rest assured that it has little romance. Key and Yuri's occasional dates are a source of comedy rather conflict.
I like Casshern/Casshan. The history of a boy-turned-robot to fight the robot army that has enslaved humanity, and who in turn is hated for the people that he is trying to protect ("Not all robots are bad", he says, but nobody listens). If you find it too old, there are newer versions with a different tone: Casshern Robot Hunter and Casshern Sins.
City Hunter is a comedy/action series starred by a private eye/hitman that is a riot. Ryo's personality has three settings: slobbering pervert, childish clown and badass (when he gets serious). It has romance, but not real love triangle. If you ship RyoxKaori, you are sure. There is NO asspulls here.
Battle Angel Alita/Gunnm is not a mecha series but it is cyberpunk sci-fi. If you like strong female characters and cyborgs with existential problems fighting bloody battles in a post-apocalyptic setting, I think that you will like this series. Note: the -flawed but good- ending of the original manga was changed because the author wanted to write a sequel. A lot of fans think that Last Order is way inferior.
More mecha series... Xabungle and Daitarn-3 are another Tomino mecha series. They are funny parodies of the genre.
Tomino also created L-Gaim, but... it is not bad, but it might be better. And I found the love triangle tedious. Let's tell the main female characters were turned into idiots when Daba -the main character- was in the vicinity.
Have you watched Escaflowne? Galient uses a similar idea (mechas in a medieval setting) I pretty liked it.
I see that you have already watched Robotech/Macross. Orguss is similar (it was meant to be the third super-dimension series after Macross and Southern Cross, actually), but I am not sure about it. The action is good, the machines are cool, but the love triangle is very annoying.
Another Seinen series that I like is Sanctuary. It is a political and yakuza drama.
Have you checked Berserk? It likes a lot of people, but I am not too enthused with it.
Saint Seiya is an mythology/action series where Greek and Norse gods choose human champions to fight their wars, train them to gain super-human abilities and grant them mystical armours. It is one of my favorite series since that I was a kid, and I love the concept, but it is very flawed. If you check it, I advice watching the Sanctuary anime adaptation, the Asgard arc filler, and then switching to the manga and reading the last two arcs (Poseidon and Hades).
I will give more recommendations when I have more time.