I'm installing replacement windows but want to keep out the cold & heat

Depends on preference and $$ available. I'd go with Pella or Anderson and if it is really cold, triple pane. Go with Argon but you may see no benefit from Low-E

I just bought 21 replacement windows and the price ranged from $11,000 to $19,000, all thermopane. If you want better you can pay more for triple pane and gas filled but each extra dollar spent after thermopane will provide diminishing returns. If you think you may move in less than 10 years do not go overboard.

You can buy a good replacement window and save a lot of $$ by DIY. I just changed my daughters and they were in the $200 each range with little extra cost. In GA, we have to use Low-E argon.

Any windows u buy are only as good as the installation. If not installed correctly u will still have drafts.

A name brand will cost a little more, but will give u a better return when selling house. Also getting parts for repairs will be easier.

If u are going to do installation, check back with us for right way to install.

Good luck

Chuck