Most all of them suck, but the NASM is one of the most well known.

The NSCA CSCS (and its brother Cert I can't remember off the top of my head) are also up there with the one Trevor mentioned. Though, as he said, each isn't without their flaws and drawbacks.

CSCS is good, but correct me if I'm wrong, it requires a college degree of some sort in the field of excercise, right?

I went through NASM for my PT training. Its definitely focused on their “OPT” method, which is good for the regular joe who wants to be functionally stronger, but not that good for strength, performance, or hypertrophy training. They have specialized programs for that, but I'm waiting to get into BPAK's HMAX coaching certification, in the mean time I'm getting a degree in Health and Human Performance.

I would like to become a personal trainer at my local gym.However there are dozens of certification programs out their which one is best? or which ones should I look into?I've heard of ISSA, NCCPT, NASM, etc?

If you're going to become a personal trainer at your local gym, I am of the opinion that any certification will work since you will have to use the gyms protocols for training and you'll be required to meet a certain quota of sales.  I'm surprised that the gym would even require certification.

Its different from state to state based on liability purposes and potential state or franchise mandates. I know 24 hour fitness offers a $299 crash course for PT Cert that takes a weekend... but you get what you pay for. NASM Is one of the most widely accepted for big box gyms, because it's like lukewarm water, great at nothing, can work for whatever. Personally I say test the waters in as much as possible, theres always going to be great info out there. None are completely right, nor completely wrong.