In the last few years two products risen to the front as real contenders to the OS X crown.
iNMR Reader is suitable for most general 1D and some 2D applications is ideal for the PhD student or Post-Doc who wants an economic solution for their personal computer. Price € 50 for the first copy and €30 for each additional copy on the same order
MNova is much more polished and very capable of complex analysis and production of publication quality figures with its higher price tag is aimed primarily as a laboratory purchase. Price €305 for the full version and €105 for the lite version.
UPDATE: Thank you to Marcello for pointing out that there are great reviews on both these products at the nmr-software blog