Mind you I've never had a head light go bad on me ever... My driver side light is dull and the high beam doesn't even work. It's not even a low beam brightness, it's just a dull yellow.. would this be an indication to replace the bulb? Obviously if I'm doing one do the other side too... Is it worth it to spend the extra dollars and get the brightest bulbs or just go with the standard bulbs?
2002 F150

The brighter bulbs have less hours of run time on them versus the standard bulbs.
I will say this though, if you do end up replacing the headlight fixtures. Buy OEM Ford from Rock Auto, Ebay, amazon ,,,,, who ever. Because the cheaper aftermarket [censored] like Eagle Eye AKA Dorman ...etc. and these others suck, they will crack in the cold winter, or the molding inside will be bad so instead of getting a solid beam you will get 2 or 3 round circles of light beam on the ground. I have dealt with this several times with customers that replace the fixture and then think they screwed something up, but in reality its the cheap non oem light fixture that is bad.

All my head light buckets are OEM.. I had the HID lights and couldn't get them out quick enough.

sounds like a bad ground

With their age, I would replace both at the same time. Stick with OEM.

Yea I remember a while back you replacing the aftermarket headlights. If you put new OEM assemblies in then unless there has been sever weather deteriation and the lenses are yellowed or distorted then I would start with replacing the lamps with an OEM level type lamp. I hate the bright blue lights some have used as they have a blinding effect to me. (JMHO). If that doesn't fix it then start checking connectors/harnesses back. Since it sounds like just one side it could very well be a grounding issue.

Ok so it was the bulbs... I replaced them both. Well after fighting with the latches, it was the bulbs. I was shocked since the bulbs were not that old... But much happier now and I even replaced the back up lights with LED bulbs, what a difference...

I like the Silverstar bulbs. I've never had to replace the headlight fixtures themselves.

That's what I picked up at pep boys... I really don't notice a difference in brightness but they are done..