If I were you I would probably go with the PPO gold plan.
HDHPs with HSAs are good deals when you pay a significant portion of the insurance premium. You accept higher financial risk in exchange for the tax benefit of the HSA and the potential that you can save money if you incur no significant medical expenses. Worst case scenario, you incur large medical bills, hit the out of pocket max, and you likely aren't out any more than you would have been had you had a pricey traditional insurance plan.
But yours are an unusual case where you pay none of the premium costs. To get the tax benefits of the HSA you have to accept significantly higher financial risk
but you get no premium savings in return to offset the risk. Sure, you can get a small tax benefit but in the unlikely event you incur significant medical expenses, you are on the hook for significantly more.
Odds are, you are young and healthy and will consume a relatively little healthcare. With the HDHP, even if you go to the doctor once or twice for minor ailments, you will be paying hundreds of dollars because you get no help from insurance until you hit the deductible. Any tax savings you gain by having the HSA could quickly be erased by even minor medical expenses. With the Gold plan, though, you pay a $10 copay for an office visit and get generic prescriptions for free.
I'd take the Gold plan, count my blessings, and find other ways to save on taxes. Remember that taxes are the tail of the dog that is your financial well being. Don't let the tail wag the dog.
The best plan for you would be the HMO plan with almost no cost sharing.
. . .
I could see someone wanting a richer plan but not the restrictions of a closed-network plan, and would therefore choose the PPO Gold. I have no idea why someone would choose PPO silver under that type of arrangement.
I completely agree with this assessment. HMO is best financially speaking, but I am wary of the restrictions imposed by HMOs. But there is a good chance my wariness is irrational and based only on the horror stories of HMOs from yesteryear. Investigate the network of available care providers and the likelihood that you would end up out of network. If you are comfortable with the availability of covered care, then by all means take the HMO, but buyer beware.