what's a good gateway for these games.
I haven't really tried any sort of Warriors game since the PS2 . Should I try out any of the spin offs first (Gundam, Fist of the North Star), or Sengoku Basara, or what. This shit seems impenetrable to a guy who's been out of it for a decade plus.
I agree with Bebpo- Start with Warriors Orochi 3. There's multiple versions of this game out there-- the most recent -and last- version of the game is Warriors Orochi 3 Ultimate, which is available on PS3, PS4, Vita, and Xbone. Warriors Orochi 3 has all the characters from Dynasty Warriors (up to DW7XL/Empires) and Samurai Warriors (up to SW3XL), plus its own unique characters and guest characters from other games, including all of the playable characters from Ninja Gaiden 1-3.
Dynasty Warriors 8 XL and Samurai Warriors 4 are both new starts for their respective series. You could also start with either of those, but I'd still go with WO3U simply because it offers a massive character roster and hours upon hours of game play, plus feels like a good mix of older and newer musou game play.
TBH you really can't go wrong with any of the recent Koei musou games. They're all pretty well made and you'll know what to expect from any of them. The main differences are in the game play systems and how action or strategy oriented they are. Samurai Warriors 4 is more action-oriented, which I loved, but some of the other members here were turned off by this. I would avoid the second Fist Of The North Star game (it's total crap) and would skip the first One Piece game in favor of its much better sequel. If you have a Wii U, Hyrule Warriors is also an excellent title and good fusion of Zelda and musou game play.
Sengoku Basara is made by Capcom and doesn't quite play the same way as the Koei games do. It's much more of a straight-out beat-em-up compared to most of the Koei games, and also completely insane/over-the-top in a lot of its design. Only the first game, heavily changed up and released as "Devil Kings" on PS2, and the third game, released on PS3 and Wii, made it over here, though. The third game got a Japanese-only expansion and Sengoku Basara 4, which is easily the best in the series, came out earlier this year.
Fist Of The North Star: Ken's Rage is also more beat-em-up like in its story mode level progression, although it does offer a more traditional musou-style mode where you have to capture/defend territory points too. I enjoyed it quite a bit, although I like I said, avoid the shitty sequel.
Also, when you typically see someone bash these games as "mindless button-mashers," it's because they're playing them on normal or easier difficulty levels. These games are better served on harder difficulties, otherwise there isn't as much challenge, if any.