Is there no guide on what order is recommended to play this? I kinda wanna start from something more recent and fappable
The first game is, well, quite better with remaster. There's a huge difference between original and remastered - you might as well just play them both, it's two different games.
The second game, as far as i know, has a faithful remaster. So it's more about what style of art you prefer. Looks like the only thing that's not faithful is Rance's look, which is made to be closer to Sengoku and the first game's remaster.
Then the third
(and by music and designs alone it clearly doesn't have a faithful remaster, but it's yet to be translated), fourth, 4.1, 4.2. Now here you can play Kichikuou, which is an alternative ending to the series. But without it, the next game would be Rance 5, and then it's straight 6, 7, 8, 9, 10.
1-3 are very short, with 4 being longer, 5 being a russian roulette, and then 6-10 getting bigger and bigger. Kichikuou is pretty sizable as well, but nothing like 6-10. 1-5 games are probably shorter than 6 alone.
EDIT: Well damn, i've only read the last part now. Something more recent and fappable... i'd say 6 and 8. Still have some pics from them saved. Also 4, not many know, but it even has a cuckquean fetish, which is incredibly rare even now, yet TADA somehow managed to do that in the ancient times. The order of games is straight, 1-10, so you'll skip some character introduction if you'll just jump in the middle. 1 and 2 introduce important people, 3 introduces main antagonists, 4 introduces setting of the world a bit more, 4.1, 4.2 - one important character, 5 - one character as well.