And just finished the main route in Sengoku. Hat's off, this has genuinely been a really impressive game, worthy of the hype attributed to it. Are the other routes worth bothering with? I'm eager to try out the other games in the series now, but if there's decent amount of content I could blast through it again a few times.
I suggest playing from 02 to Rance VI, and then replay Sengoku Rance after VI and you will enjoy Sengoku Rance even more.
Suggested order:
Rance 02 (English fan translation) -> A short dungeon crawler adventure, but important characters for the rest of the series. Think of this as a prelude to III.
Rance III (English) / Rance 03 -> The first epic adventure in the series. 03 is a complete upgrade but only in Japanese so you can choose if you want to start learning to use machine translation tools or play the original III translated with primitive mechanics and graphics
Rance IV+4.1+4.2 (English) -> If you found the primitve mechanics in Rance III not too bad, might as well play these short adventures. If you did not like III's gameplay then go ahead and skip this one for now
Kichikou Rance (English) -> The final game of the "old" canon, this game is like Sengoku Rance with a more primitive battle system but blows SR out of the water for story and c&c. This game is a true marvel
Rance 5D (English) -> Another short comic adventure, consider it a prelude to VI. Some people hate it's weird battle system/ plot system but I think it's super underrated
Rance VI (English) -> The second great epic adventure of the series (not counting KR), this game has a truly great story and is one of my favorite rpgs of all time. It shows what can be achieved by a blobber with a real plot
***Sengoku Rance***
The final three games of the series should be played in order and currently can not be played in English, requiring use of machine translation. So if you didn't buy into machine translation for 03, this is now the only option if you wish to continue (in English. There are Chinese and I assume Korean translations for RQM and IX).
Rance Quest Magnum
Rance IX
Rance X