I've developed a bit of a fascination with this genre after playing Shattered Steel and Shogo: Mobile Armored Division on this site, and I'm wondering if there are any other good mech-simulator games out there (besides Mechwarrior). It's a genre I don't hear much about these days, so I'm curious about what's available.

The only other mech-simulator game that I could remember is Heavy Gear series.

There's the [url=http://www.mobygames.com/game/windows/earthsiege-2]series.
And G-Nome.
[url=http://en.wikipedia.org/wiki/Category:Mecha_simulation_computer_games]A list on wikipedia.[/url]

War World Tactical Combat might be up your alley.
A little more arcadey than those games that make you really have to think about making your mech walk.
Site is here: http://www.warworld.net

G-Nome is great fun if you can manage to find a copy. It has great combat and some really interesting mech designs. It also works perfectly on XP (not sure about Vista/7).
MechWarrior 4 is going to be released for free in the near future (along with all expansions and mech packs) to help promote the upcoming MechWarrior reboot, so that's something to look forward to.

Saw Bootfighter Windom but haven't played it. Looks very Virtual On to me.
http://mirrormoon.org/projects/windom
Along the same lines is Silver Knights which recently got updated.

Heh, not long after the announcement I found a sealed retail copy, sold as "used" for ca. $4.50. It's awesome.

Not really, no. It was more like a shooter game in which you were 100 ft. tall half the time.
Thanks, everyone. That wiki list in particular looks very useful... and I do like freeware.

how is the pc port? does it control bearably?

I LOVE Battle Engine Aquila!!
I generally dont care for RTS (it has some elements) or mech games but somehow I fell in love with this one instantly.

It's been several years since I've played it, but I don't remember having trouble with the controls.

Red Faction: Guerrilla has plenty of mech/tank scenarios that are tons of fun. I think its my favorite recent release as of late, you could try it out.
Its not only mechs though, but when you come across the Heavy Metal actions, you can hop in a mech and have fun, they are monsters in the game.
BF 2142 has walkers which are like mechs too, sorry don't know any old games with them.

I really wanted to get War World, but there seems to be a lack of a solid online population, therefore defeating the purpose of getting the game.
Also, you guys should check this out:
http://www.akithgames.com/
Words cannot describe how amazing this game is.

I'll second Heavy Gear. There is also Heavy Gear 2. Much like Mechwarrior 2.
If you have a 360, Chromehounds is probably the best mech game since Steel Battalion (that I still threaten to buy off of Ebay).
On the original Xbox (not backwards compat) is GunGriffon: Allied Strike that's a pretty nicely done mech game, more sim than arcade. Graphics are a little outdated even for when it came out, but a good game.
Shattered Steel is here at gog for cheap, but I haven't spent much time with it yet.