I did a lot of research on https://dmarket.com/ingame-items/item-list/csgo-skins/rifle/ak-49 and the AK-50 and AK-51 listings. The AK-49 skins tend to be more classic and understated, great if you like a traditional look. AK-50 skins are usually more flashy and modern, which can make you stand out. AK-51 offers a sleek, balanced style somewhere in between. In terms of popularity, the AK-50 skins often have higher prices due to their striking designs. For competitive play, it’s more about personal taste, but for collectors, rarity and condition really matter more than the rifle model.