1. Futoku no Guild: best adventurer in a small-ish town realizes all his colleagues are quitting monster hunting to get married and he should, too, but first he needs to train a replacement. The problem is all his options are useless girls that are only good as monster bait, also apparently monsters love sucking tits and pussy for mana instead of just eating them outright. Pretty good stuff.
Genkai level 1 etc: guy get isekai'd, has a max level cap of 1, throw into the chasm of dark unending despair and death by the dickhead king. Find out he can absorb corpses to gain power, gets kind strong, is rescued by and lives with a catgirl and elf stuck in a teddy bear body and eventually managed to get out of the ravine of burning hellcorpses. Not much fanservice as i recall but i saved at least one instance of titty.
3. Goshujinsama etc: guy gets isekai'd with literal fucking minecraft powers in an area with only demi-humans who hate humans because they abuse all the non-humans. Is found by a dark elf, proves his worth and isekai nature, is voluntarily made a fake slave so nobody in town fucks with him, and then it turns out the dark elf gets real horny at night. I'm rather fond of it.
4. Hazure something kenja time something: guy can't seem to achieve a mid-tier class after maxing out all the lower ones, gets kicked out of his party, is taken to a brothel to cheer him up and it turns out he can class change to a sage temporarily after having sex. Proceeds to fuck girls to power up when needed.
5. Isekai Affair: guy gets isekai'd with a huge cock, beats the demon lord, and ends up in a somewhat loveless marriage with the princess because his cock's just too big for her. Proceeds to meet up with his female warrior former party member, who's widowed from having married the party's skinny middle-aged wizard, and i forget how but they start fucking. Pretty hot, kinda short, has an unrelated sequel that i haven't kept up with.