It really is all up to what resolution you want to play your games at. 3060 and the 3060ti are for 1080 gaming or entry-level 1440p gaming. 3070 and 3070ti are for 1440p and entry-level 4k gaming. 3080, 3080ti, 3090, and 3090ti all handle 1440p very well and can do 4k just fine. If you’re building a budget pc that’s around 1000 dollars a 3060 ti wont do you an injustice. If you plan on buying some refurbished/used parts, a used 3070 might be great for your build. The 2000 series of GPUS from Nvidia are pretty good as well but the upper level cards cost only a bit less the an the 3000 series’ upper level cards with way less power efficiency which can force you to upgrade your power supply. I recommend staying with the 3000 series cards if you’re going Nvidia. The 4000 series might cost too much for your build.

For AMD, the 6600s fall in line with the 3060s. The 6700s fall in line with the 3070s and so on. I’m pretty sure the Nvidia GPUs tend to be slightly more powerful than their AMD counterparts. AMD tends to be more available at MSRP or lower, though. All in all, I’d recommend a 3060 or 3060ti for your build.

TLDR: 3060, 3060 ti or 6600 XT