I know you pref western but the west pails in comparison to Japan when it comes to decent bondage games. I'll only include games with full or close to english translations.
1. Moral Swordswoman Asagi is great, bondage combat system and tons of scenes, this is the best game for me, for an RPGmaker game its huge with tons of stuff to explore. (Translation is pretty much done but I even enjoyed playing through this without it.) There is also another game which to my knowledge isn't translated which is an improved version of the combat system in Asagi but is 1/10th the length (search
鎮魔剣風伝アオイ its basic test for his new combat system and doesn't need to be translated to play)
2. Lilitales - Story is about a Princess taken as a sex slave and her fallen from grace childhood friend and sworn protector (also female) trying to save her, tons of bondage and slavery with great art and full translation.
3. Shinobi Buster Mizuna Ninpocho - Good art and animated scenes but is not as bondage heavy as the other two but has some good scenes and early on, has a full translation.
Western wise, other than modded skyrim (which is great but takes time to learn how to do correctly) most games have a few bondage scenes behind a ton of stuff which doesn't interest me.
