I'm looking to get one more champion for top lane before I start really focusing on picking champs for other lanes.

The main thing I'm looking for is a champion that isn't squishy, deals physical damage, and deals good damage throughout the entire game. I have enough tanks and magic damage dealers for top, so now I need someone who deals physical damage and can contribute to the team's damage output at all stages of the game.

I've already considered Irelia and Nasus, but I found Irelia boring (too auto attack reliant) and simply felt weird to play. I just have no interest in Nasus.

So are some good physical damage dealers that don't fall off lategame while still remaining somewhat tanky/useful to the team?

Auto attackers like irelia and nasus are the ones that don't fall off late, ad casters and tanks obviously do. If you don't want an auto attacker then you aren't going to find a lategame hyper carry. Jax or Olaf maybe? Riven falls off some but is another good one.

Not sure if it's what you're looking for but Poppy is one of the best 6-item champs in the game. She deals a mixture of magic and physical damage and is as much an assassin as a tank, but she definitely scales into late game.

bruisers are by definition supposed to fall off late game.

Unless of course you're mixing up melee carries with actual bruisers like Garen and Yorick.

i would have to say riven

Jax
Irelia
Riven

Those would be my top three, but I don't play a lot of bruisers.

well, the main reason I'm not interested AA oriented bruisers is because it always feels like you just turn on your steroids and right click the enemy (obviously I'm simplifying it, but you get the gist). Riven, for example, gets most of her damage from her AA's when boosted by her passive (at least from what I've heard), so she might be fun despite being AA oriented, if that makes any sense.

That said, not sure I'm actually interested in Riven, I have enough 6300 champions for a while, I'd rather focus on rounding out my roster with some cheaper champions right now.

AD Sion has a terrific lategame, but his earlygame is awkward, especially solo top.

If you're duo queueing with a good jungler, though, he can be a terror up top.

Bruisers i can say you got lee(maybe) yorik and ofc nasus, now champs like riven and jax i dont consider bruisers because they fit the hyper carry bill too easily.

Your asking for too much. You want to be tanky do a lot of damage and you reject all the normal champion selections 0_0. That being said, Olaf is pretty good late, and does really well in lane against a lot of popular picks.