if yours is an automatic 190e2.6, then you have no problem. Like the other guys said, you can go for the 94+ C280 (which is more refined in every way than the W201), or the W124 300E/E320.

but mine is a 5spd manual 190e2.6 and I cannot find a suitable replacement for it that is a "spritual successor", which I define as having an inline-6 and a 5spd manual. And affordable to me. The only thing that comes close (actually a step up in many areas) is the 5spd 300E, which is quite rare.

though the car has its quirks, I love it and can't imagine parting with it. But rather than replacing it, I would imagine getting a companion car with a different character. The E320 or 400E/E420 comes to mind. You need one car to appreciate the other more.

for me, the only real replacement for my car would be a manual BMW 325i/328i (previous generation). Or a manual Euro C280 Sport.