Like Merlin, I also upgraded my HP laptop with an Intel AC7260. You have to insure that your computer's bios will accept it (most laptop manufacturers encode a "whitelist" into the bios, so that only certain "approved" wireless adapters will work...if your card is not on the whitelist, the only way to make it work is to flash a modded bios, and that can be very risky, as in you can brick your computer, so I wouldn't recommend it).
The AC7260 is cheap (about $35-40 from Amazon) and it's really easy to install (basically, find the card in your laptop, take out the screws holding it in place, pop it out and replace it with the AC7260). Make sure that you have a card with two antenna wires, because the card is a 2x2. You also need the correct driver. Use one from your laptop manufacturer, or get the latest one from Intel.
I've also used the Asus AC53USB and AC56USB and they are very good, actually better and more consistent than the 7260; the only inconvenience is they are external cards and the drivers take a bit longer to load each time at bootup than an internal card's drivers and it also requires unplugging when you pack your laptop to go.
My wife is also using the Asus USB-AC51 in her HP laptop (the Intel AC7260 was blocked by her laptop's bios so it wouldn't work). The performance on this adapter is not much faster than a really good 11n card, but the fact that it's 11ac keeps our 5ghz channels running all 11ac at 80mhz.
I have used and compared the performance of every wireless USB AC adapter currently on the market that I could get my hands on at my local Fry's....D-Link, Edimax, Trendnet, Linksys, EnGenius, Amped, and Netgear, and without question, all of the Asus USB adapters provided superior performance, higher throughput, higher link connection rates (comparing each class to class, i.e., 1200 to 1200, etc.). Edimax was probably the next best in terms of performance, but it's large and the weird antenna just wasn't something I could deal with (I like to use my laptop literally on my lap, and I move around a lot and the antenna design just seemed a bit fragile).
If you want internal, the Intel AC7260 is really the only viable and cost-effective option out there. If you want a USB, then any of the Asus adapters will work great. The are pricey, but worth it.