Let's see... for the even ones, II is among the worst, IV is a classic, VI is a masterpiece, VIII is a weird and experimental fever dream but great nonetheless, X is also a masterpiece and my favorite in the series, I absolutely cannot stand XII, and XIV is an MMO, thus I've never played it and can't count it.
For the odd ones, I is obviously important but hasn't held up all that well IMO, III is formative gameplay-wise but a slog, I personally never cared for V, VII is an absolute classic despite its modern-day blemishes, IX is among the best in the series, I also can't count XI, I love and thoroughly enjoyed XIII, and I had a great time with XV despite its flaws.
I guess they kind of work out evenly for me, with both sets having four games I like or love. It's hard for me to choose between X and XIII because I adore them both, but X is ultimately my favorite in the series and comes with VI, IV, and VIII, which has my favorite soundtrack in the series, so I gotta go with even. Not by much, though.