mate, i was in the same position as you in the past for few times. I think it comes down to you and what you want. get a piece of paper and put down the advantages and disadvantages of both jobs. take in consideration all factors like: What are the opportunities in both jobs (more money, moving up the scale, organisational culture, how serious is the company, any bad experiences with previous employees, MONEY again, the boss and so forth.). You mentioned that the new one is offering more money but what do you need to offer for more money? Also, is the new work environment better? is the new job really new for you? do you get more responsibilities? is there an opportunity in the new company to move up, or you will remain in the same position? Are you replaceble? Remember that if you're not replaceble than you wont move up... :D. Is it closer to where you live? You might get more money but if you spend that extra on petrol, it's not good. Is the new firm going to pay for insurance or any other expenditures from your behalf?
So it's totally up to you mate. I hope I didn't confuse you a bit more than you were.
Good luck. Keep me updated.