A collection of stories I've personally enjoyed about an OP MC in a variety of different situations. Usually an isekai or reincarnation.
Tends to avoid harem (or blatant romance) but there may be one or two. Trigger warnings will be added. A blatantly self-indulgent list in no particular order.
Part Two is here:
https://www.mangago.me/home/mangalist/2214953/