Megazone 23

Both products of the 1980's OVA boom, Bubblegum Crisis and Megazone 23 are each tales of man's ambiguous identity in a not-so-distant future. 

both world is control by a computer and the world isnt want it seems and the rest of the world doesnt know but Megazone 23 predates the matric by a lot of years 

While there are many differences between the two, they both feature a secret, and there is some slight similarity in the secrets (saying more would give too much away). There is another similarity, but telling you about it would also be a spoiler for one of them. I would also consider both of them required viewing. 

These are both exciting cyberpunk action anime that deal with themes of AI and Identity, they share 80's animation styles and interesting science fiction concepts. 

hommage to the popculture a la 1985 

Both are interesting cyberpunk adventures with twists, awesome 80's style, exciting action, and motorcycle chase sequences.  

same in good music tracks and sci/fi story´s, but macross flashback 2012 is more directed to music compared to Megazone, and an macross compilation of previous events in that timeline 

Cool bikes, biker gangs, hot 80's girls, 1980's culture BUT it's the future, and war disrupting it all. Both Venus Wars and Megazone 23 are oh so 80's, but oh so great! They feature amazing 80's pop (some of the best anime has to offer), they have great stories to tell (both are classics) and feature cool characters doing cool things. Also both shows are quite smart, very sexy, and the art/animation still looks amazing. You owe it to yourself to check the other one out!  

Similiar animation style and feel (at times). Area 88 is much better, but if you like first 3 OVAs of Megazone, you'll really like Area 88 OVA. 

Both works - mecha anime with cyberpunk elements. Both slightly similar to the "Matrix" movie: MC learns the true about nature surrounding reality world. 

Many similarity, such as bikes and colonization in space etc, but Megazone 23 have more mature content. I also think the plot have something in common and it was pretty enjoyable to watch them both. 

Both have the same aspect in which anime people's lives are controlled by computers and later on, rebel against it. Megazone 23 rebels from the underground, while Grey: Digital Target rebels above ground. Megazone 23 is friggin cooler though.