Simms. Great fit and excellent quality. 1 year no questions asked warranty and excellent customer service. They will also do repair for a reasonable price after the first year.
I am on my second pair of G3's. First pair went strong for 4 years of 100+ days on the water with some minor repairs. They still have some life left in them, I'm sending them into get the crotch patched, then they will be used for waters infected with invasive species while the new pair is used for everything else.
That said, I think waders are one of the things you should really invest in. You'll spend a lot of time in wearing them, you want to be comfortable and have free range of motion. In the colder months staying dry is critical for safety, a good pair of waders will go a long way, but you also need a good pair of boots with studs. If you don't stay on your feet, no pair of waders will keep you dry.
Spend as much as you are comfortable spending, but get the best you can afford within your budget. Generally, I spend the most money on gear that is going to make the biggest difference and skimp on other things. I put more money into the items that keep me warm and dry on the water, and that make a noticeable difference in catching fish. I buy the best waders and boots I can afford and use a cheap net. I use mid-priced rods and reels, but the best fly lines. I use cheap fly boxes ($3 plastic plano boxes) rather than $20-$30 fly boxes; you get the idea.