How can I improve power quality into my house?
Once the basics (grounding, ground-neutral bonding) have been checked, your options with respect to the power company will depend on where you are - in many places there is a public utilities commission (or similar) that may be able to make them take action if they will not do so on their own.

You can rent a power line monitor/recorder to verify if there are issues with your incoming power. They are not stunningly inexpensive to rent, and you'll be better off if the power company can be convinced to park one of their monitors on your line rather than you having to rent one; but it's the only way to actually verify power quality problems - both if there are any, and what type they are.

I personally use several/multiple surge suppressors and surge capacitors (the "surge capacitor" is also labeled as a "facility EMI filter") but without knowing what actual power problems you have, it's difficult to say if those would solve your problems. (Just a happy customer - shop around, you can do better than list price.) They (or similar products mentioned by Ed Beal) certainly would not hurt, and MIGHT help; if DIY installed they will cost considerably less than a week's rental of a power line monitor, based on a quick look for those.