I am going to get a set of wheels for my 1998 200 SX SE. What is the best all around rim size. I'm thinking 16 X__. Seventeen's would be nice but will they be too big?

Depends on what you're looking for. Appearance or performance.
For looks, 17's will work fine.
If you want peformance it's 15's.
That's why I have 16's.

heres 17 on my old car http://www.nissanperformancemag.com/january01/images/good_side.jpg as far as performance you cna put 17's on but look for something lightweight like a volk..$$$ but 15"chrome will be alot more weight then a 17 racing wheel