Ochel nefesh supposedly refers to the permissibility during Yom Tov of doing melachos that "cause personal pleasure."
No, of course not; it's after all the rabbis who decide what "personal pleasure" is, or is supposed to be. (@Msh210 notes: "I don't think it means 'pleasure to your person'. I think it means 'pleasure of the person (body)' as opposed to intellectual or other pleasure.") However, do one's own tastes and responses enter the halachic picture at all? That is, if something--let's say, taking a bath--gave me great pleasure, but involved doing a melacha during Yom Tov, could there be any halachic justification for doing it even if it is not on the official list? Inversely, if I hated a particular food, would I be allowed to prepare it for myself during Yom Tov in the name of ochel nefesh?
For the sake of argument, let's assume we are talking about rabbinically-defined melachos rather than Biblical ones.
Related (please don't judge harshly; this is a real problem for me): How to have an easier time with Yom Tov?