Which surround receiver should I choose to upgrade my home system?

It really depends on how much you want to spend and how much space you have, because entry-level receivers are cheap but might not have all the connections you need, while the fancier ones start at a lot of money. Try checking out brands like Denon or Yamaha - they strike a good balance between quality and price. But honestly, if your budget is really tight, lesser-known brands work decently too.

Before you jump into buying a new receiver, try checking if the one you already have supports at least HDMI passthrough for surround audio - might save you some unnecessary cash. If you really do need to change it, here's a trick not many people think about: check whether the model you like has RCA analog inputs alongside the digital ones. If you've got old devices hanging around the house, that'll come in handy later. Then yeah, consider the space and your budget, but honestly integrated WiFi connectivity is pretty much standard even in mid-range models these days, so it's not a luxury like it used to be years ago.