^^^^This^^^^
Normal size in games/VN's hides more of the actual penetrations so a slightly larger than normal is a must in VN's/Games.
Big enough to be able to see it going in and out of the vigina.
I mean. If its a choice specifically between big or small I would choose big. I prefer them to be realistic in size, but I also dont like seeing them super small. It kind of feels weird.
I'm much more off an average/larger than average size type off guy but when the artstyle is right i might like them oversized (like i think kemopop(hand drawn gay game) is great but any koikatsu game with oversized cocks is a turn off for me)
Generally I prefer larger, even comically so, to smaller on male characters. On futas and trans characters, I prefer any size from tiny to (realistically) large. Cockmonster futas are a little too-over the top.
Honestly at this point I'm just tired of the overused trope of a character seeing MC's dick and immediately falling in love because it's the biggest one they saw in their lives. So I definitely prefer anything a little more realistic and proportional, like something that wouldn't freak you out if you saw in real life.