I have one AP on the west side of the house pointing east, and one of the east side pointing west... great signal everywhere. Don't have ethernet in the walls? Run it. I took 4 hours out of a Saturday to buy cable, fish tape, a crimp tool, some ends and some wall outlets and wired up my whole house with the help of youtube. No, I don't do that for work. Oh, and I had to get a 12 inch drill bit, apparently I have 3 2by4s in a row up in the ceiling.
Honestly, just don't settle for the shitty router that your service came with, get that damn thing out from behind the TV or wherever it shouldn't be, get it up close to the ceiling somehow, and you'll probably never want to use a fishtape even if you can.
Mesh networks are probably the solution for apartment dwellers. The routers all act as one router but are separate smaller routers that talk to each other so you can put them all around the house, and you just need to plug them into power. No mods to the apartment are required, it's all wireless. The catch is expense, but if you buy once, and cry once, then it becomes like a piece of nice furniture that moves with you.
But again, one $40 modern router that isn't the shitty combo unit from the ISP, keep it up high and unblocked, get enough extra Cat cable to reach where you put it, and you might be happy enough with that.
Hell, get the router out from behind the TV if that's where you put it (everyone tries putting it there to hide it) and you might get all the signal you need.
Powerline has much better latency (and much more consistent latency) than wifi, so it'll give you a better experience for stuff like gaming. Depending on how exactly your house is wired and what else you have on the circuit it can have reliability problems (although if you live in a dense area wifi isn't exactly reliable), but if your house is suitable it works very well, I used it about 5 years with no problems.
I'm currently using powerline because running an ethernet cable across the apartment seemed gaudy at best. The suggestion of a flat white cable stuck to the wall seems interesting.
I have the modem and router on a UPS because power flickers semi-regularly here. Sadly, powerline cannot go on a UPS.
I've been renting for the past 7 years. You can buy flat, white Ethernet cables that can be fixed to the walls with sticky clips. It's less ugly than the round cables and while obviously not earthquake proof, the clips do a fairly good job at keeping the cable in the corner.
Powerline ethernet uses your existing electrical cables as the network cables, but on a different frequency. Beware when using in shared units such as apartments.
If you live somewhere that'll let you then access to a crawlspace like an attic will let you do this
For example at my place getting into the above house crawlspace lets me access the insides of my walls from above. Simply run Ethernet from above where you'll want each end of a plug to be, then drop it down and put it in place through a cheap (like .45c) Ethernet wall adapter. Hardest part is cutting the hole into your wall for said wall plug
I'm simplifying a bit but honestly it's incredibly easy to buy a length of Ethernet wiring and some rj-45s, Google how to wire them, and run it yourself. I ran a short wire across a room once and it only took like an hour. Would be less in future now that I have experience