i dont really pay attention to whats popular bc i try to avoid it, so idk if my opinions are agreeable.
sam and dean—of course—they are the predominant ship i care for, id say the other ships i like are to a smaller degree.
other then that, i like sam/castiel the most of any outside-of-wincest ship. i do dabble in sam/crowley just because theyre fun.
most of my liking for sam and castiel centers around demonblood!sam. i enjoy the idea of an angel meeting such a deep believer while they have demon blood coursing through their veins, that they were cursed with rather than having with their own volition. cass having some kind of moral dilemma of not understanding how he can be expected to forsake someone as sweet as sam for having evil in him that was forced upon him, while also hating that sam is participating in furthering it.
i find sam/lucifer corruptly enjoyable as well and i love to read fics of them, but i dont like them as a ship in the sense that id want them to ever actually be together in the show lmao. i just find their dynamic and connection deeply interesting and i think especially in s5 its super intriguing.
all in all, most of the ships i like are sam-centric 𐔌*ˊᵕˋ*𐦯