I use Neat Image myself however one thing I've picked up about noise reuction software is that many of the options - Noise Ninja; Topaz Denoize; Neat Image and others - are all pretty even on performance (provided that the operator knows how to use the software of course).
What is different is that some noise programs will work slightly better on some shots - however for most people the time and cost of investing in multiple noise reduction software options makes in inpractical to use all the options. So my advice is make your choice and then spend a good amount of time learning to use the program really well.