Thing that I refuse to go cheap on

Anyone who knows me would say that I am a frugal person.  I will get a lemon water with my meal when eating out, I look for the best deals and use coupons in order to maximize my savings, I will wait for a movie to make it to the "dollar theater" so that I don't pay 10 times as much to see the same movie (it usually hits the dollar theater a few weeks later) and I even sneak snacks into the movie theater since they make their profit by jacking up the price on snacks. That said there are some things that I absolutely refuse to be frugal about.

• A bed - I have back problems from a mixture of scoliosis and a bad car accident back in March 2010.  I will admit that I tried to save money by sleeping on an air mattress and my back was killing me.  My then boyfriend (now fiance) said that I needed to buy a quality mattress or else my back would get worse and I am so thankful that he made me go buy it.  It ended up costing me $750 (it was a queen-sized Serta) but I don't regret the decision at all!  It was heaven!!  
• A car - My first 3 cars were junkers and although I didn't spend much to buy them I spent a lot in repairs.  After my second gas leak on my car (the gas line had rusted out) I decided to buy a more reliable, newer, used car.  I ended up buying a '02 Honda Civic that was in great condition.  No rust (which is rare to find on an older car in Upstate NY) and I paid cash for it :)  I had been saving up money because I knew my car would have a problem sooner or later since it was so old and since I didn't have much of a credit history I knew I would get stuck in a loan with a high interest rate and get taken advantage of.
• A house - I have not bought a house yet but I know when that time comes that I will not just buy the cheapest house because this is a huge investment and I will be living in the house for years and I don't want to regret my decision.
• Home improvements - Again, I have not had to make decisions or pay for this type of thing but when that time comes I will not skimp on quality because that will just cause problems down the road with either something breaking or it will bring down the value of the house because it "looks cheap".
• Insurance - I don't want to be in a predicament where I skimped on health insurance, or any insurance for that reason, and then when I really needed it I end up paying more out of pocket because something is not covered under the cheaper plan.  I made this mistake with the Honda because I never increased the car insurance from Liability to Full Coverage when I bought the Honda.  My earlier cars were so old and devalued that there was no point in paying more than liability on the car.  I ended up sliding on black ice on my way to work one morning and slamming into the guardrail and because I only had Liability coverage none of the repairs were covered by my insurance company.  My mechanic said that I should just try to sell it as is and I took his advice and sold it for $2800, which was less than half of what it was worth.  I ended up losing a lot of money and learned a valuable lesson. 

What is something that you refuse to be "cheap" about?