>>81427216I'd say watch them all as they're all enjoyable in their own crazy ways. Most of the series has one or two episodes subbed.
Winspector has been fully subbed (thanks Sailor Otaku, you one man beast). It's a bit more grounded, basically a police unit with some hyper-technology cop show but it's a great introduction to the franchise.
Janperson is being subbed slowly, currently at episode 14. Robot cop faces off against several evil organisations all plotting to defeat him.
Gavan, the original Metal Heroes series has a few episodes subbed and is worth a watch even if you don't like early 80s tokusatsu just to see where things started.
Metalder has been mostly subbed but I haven't seen it yet, so can't really judge it.
Blue Metal SWAT has its intro film subbed but nothing else. Basically X-COM the tokusatsu. S'fun.
Juspion has been subbed up to episode 35. Starts off quite crazily and carries on, although dumps the travelling the universe setting for being set on Earth. Has a lot more kaiju and giant robot action than the other entries here. Gives me a Red Dwarf vibe although that might be the 80s as fuck fashion that the protags wear.
