I’m in the market for my first car and I’m stuck between two cars. Either a G35 or a NA Z32 300ZX. I like both cars, but they both have their pros and cons. I know the Z32 is really hard to work on if you are working under the hood, but I prefer the looks of the Z32 compared to the G35, and I prefer the sound of the VG30DE over the VQ35. Having 4 seats would be nice because I could use the car in more situations. I’m just looking for your opinions and any info that may help me make a decision.

I've owned both. Both are solid cars, but if it's your first car, and all other things are equal (cost, condition, miles) I'd recommend the G.

Performance is no comparison - the G (even in sedan form) will clobber a Z32 in every category. Z32 values are trending up, while the G hasn't hit bottom yet.

Pick one and roll with it. You can't really screw this up. Just buy the best example you can afford. A poorly-maintained, abused car will break your bank (and your patience) in no time.

Pretty much what Greg said..

But i will take it one step further on the age difference..
While a well maintained Z32 will be more reliable /lower maintenance than a beat up G35... with the G35s being so much newer they will generally be in better mechanical shape (exceptions exist).
Hoses, line will be newer less prone to breakage etc..
Pretty much unless u are looking at an unusual cream puff with perfect obsessive maintenance and up keep Z32 the G35 can be expected to be significantly more reliable + maintainable.

Also, if budget is a big consideration or you (and I suspect it is, since u said "first car") spare parts for the G35 can be found on many junk yards since it, and several similar Nissan/Infiniti brethren, was built in large numbers by the standards of our brand.