Various Ortofon models are certainly good choices, but, it is hard to say that the tonal balance is neutral. Most of the lineup below the very top cartridges are warmer sounding than average, but does that make them not as neutral? At whatever price level applies, I like the Quintet Bronze. I tend to like the Bronze models in each lineup more than the higher priced Black model (Black models tend to be a bit thinner and a bit harsh, although they do deliver extended highs).
Again, not having any reference, I would call most Lyra cartridges not as warm as Koetsus, for example, but I cannot say if they are more or less neutral. I like several models even if they are not as warm as my ideal. I own an older Titan, although I am currently using a Transfiguration Orpheus L (a slightly warmer cartridge). If I thought the Transfiguration is closer to the ideal tonal balance, it would be my choice for being more neutral, but someone preferring the Titan would rhink the opposite.
Audio Technica makes an extensive line of cartridges that I think compete well across all of the price levels set out. As I mentioned earlier, I am impressed with the AT ART 1000 model—not as warm as a Koetsu, but warm enough for my taste and it sounds great to me; it even impressed a couple of Koetsu owning friends of mine.