@sketchy I'd recommend this as a first attempt. It's far cheaper for parts and labor.
I used to be the supply chain manager for a window company in Dallas so I know windows quite well. What will follow is likely to be way more than you ever cared to know about windows, but will hopefully help you get a better idea for what you want.
What Double D described is the IG (insulated glass) unit. All you need is an accurate measurement of the IG (not just length and width, but overall thickness) and whether or not you want an energy efficient coating (often called LoE - pronounced low E). If you have grids inside the IG then you'd also need to specify that pattern (if the grids are on the outside of the IG that's SDL (simulated divided lite), which is designed to look like the really old fashioned windows that had smaller pieces of glass held in place by wooden cross beams within the framing of the frame or sash).
A couple years ago I was on my extension ladder putting up Christmas lights when it slid out from under me. It fell into one of my windows in the front of the house and broke out an IG. Since none of the rest of the window was damaged I just ordered a new IG when I got to work and one of our service techs came to my house to install it. Total cost of repair was 2 days and about $15. Had I paid for that through a Lowes or McCoy's I'd have probably paid around $50 for the IG and $20ish for the installation. That's way cheaper than the ~$180 it would have cost for the new window plus the added labor and disposal of ripping out the old and replacing with the new.
Now, if you just have a bunch of old aluminum windows that, even with new IGs would be horribly inefficient, I'd recommend replacing them. If you're looking to sell in a few years new windows will definitely add some value to your home. This can be very expensive so you may want to do it in phases if you have a large house with a lot of windows. You don't need a premium vinyl window with a premium coating to get significant energy savings or improved value from your home. The standard glass coating in Texas is called LoE 270 (I think Guardian Glass might call theirs something else), but I think it may be migrating more to LoE 366 after Texas adopted the 2015 (I think) Energy Star recommendations a couple years ago. The reason coatings matter depending on your geography is that some coatings and coating placements within a window are designed to keep warm in versus keeping warm out. They all mitigate heat transfer to varying degrees, but the desired solar heat gain coefficient in Texas (you don't want any most of the year) is much different than it is in North Dakota (you do want some of it for most of the year).
But I digress (RIP Dr. Proctor). The point is, you are going to want a LoE coating on the IG. That's the most important feature of a window for preventing heat transfer. Argon gas inside the IG also helps and is a cheap add-on. Good value there. The idea behind argon is that it's heavier and more dense than the air we breathe so heat doesn't travel through it as easily.
Most vinyl profiles for window frames are pretty good about preventing heat transfer, but I'd stay away from the obviously cheap low-end vinyl frames. They're better than aluminum, but if you're going to be replacing windows it's worth it to upgrade to a slightly better frame because the incremental cost to purchase will be offset by energy savings. IMO, the key here is finding one you think looks good. Some frame profiles are enormous (thick and wide) and look out of place in some window openings. Those will generally be more energy efficient, but not so much more that their costs are justified unless it just looks best to you. Others are really small and basic and similarly look out of place in some window openings. Again, the cost savings on these isn't likely to be cheaper in the long run. In my experience there's very little difference in the mid-tier frames, but some of these can vary wildly in cost.
Balances are the mechanism that enables you to open a window without gravity slamming it shut the moment you let go. The best balances are made by Amesbury Truth, IMO. There are two main types of balances, block and tackle or coil. The block and tackle will be cheaper usually and will perform well, but the new coil balances they've come out with in the last few years are really nice. They're not a very good solution for windows in a new construction home b/c masons will often spray a very caustic chemical to clean off mortar from windows after they've finished laying brick. The trouble for coil balances is that chemical sometimes gets through the window into the casing where the coil is. That chemical eventually eats away at the coil until it breaks. For replacement windows there is absolutely no reason to not use this balance unless your budget simply doesn't allow for it. Depending on the size of the window, sometimes coil balances are actually cheaper than the block and tackle variety.
There's already been one anecdote about Andersen windows that wasn't good. I don't know that it's representative of all their windows (some series are simply better designed than others and easier to make well than others), but the service level sounds truly terrible and worth avoiding. Andersen is generally well regarding within the industry, though. I'd also recommend you avoid Krestmark and PlyGem windows. Krestmark were well known for poor quality when I was in the window business and PlyGem eventually subsumed my company through private equity acquisitions and mergers so I know their quality is very poor from first-hand experience. That company would be out of business if windows were all they made. The siding business keeps their doors open. They're terrible at windows.
I worked for Atrium Windows and Doors. The brand still exists and is of good quality. Even though the company is now run by PlyGem people, the designs and manufacturing processes of the windows won't have changed so the quality should still be pretty good. You may struggle getting your windows delivered on time as PlyGem has a truly awful shipping process. On the plus side, one big reason PlyGem doesn't make much money at windows is because they hand out warranty claims like Halloween candy. If something does go wrong it likely won't cost you anything other than inconvenience.
I'd recommend the 150/160 or 8100 series of Atrium windows for single hungs and the 8300 series for double hungs. I'm pretty sure PlyGem destroyed the relationship Atrium had with Lowes (about 6 months after I left they had a massive shipping disaster that had loads going to the wrong stores and entire stores getting loads lost) so you may not find them in Lowes or HD anymore. I'm pretty sure McCoy's is still a good place to get them and ABC Supply would be another one. McCoy's will have the best customer experience, IMO, from inquiry to install.
Simonton was also a fairly well regarded window brand as was MI. You might look into some of theirs as you compare and shop around. Some window people I know well and trust a lot have a very high opinion of NT Windows, though I have no personal experience with them. They're in the Rendon area SE of FW and are a smaller window manufacturer. They aren't a big national brand, but by all accounts make good windows and are run by top notch window people. I also know their vinyl supplier very well and I can guarantee you they have good quality vinyl profiles. Nobody is better than their vinyl extruder. They may be worth a look. You generally get much better quality service from good small companies too.
Hope this helps. If you have any other questions I'll be happy to try to answer them.