The best machine w/re any given hobby is the one in your hands.
This is very true right here.
I had one each of the PowerBook 500 series, excluding the 550c, never got that one. Got my first one very early 2000s, and then sold all of them off a few years ago. I will say, the 540 and 540c both had absolutely amazing displays, especially considering their age. Also nice was all of them had some upgraded ram, from 8MB to 36MB.
In the end, I decided to get rid of the 520, 520c, 540, and 540c because all 4 of mine were in good operational condition and physical condition. No working batteries though. Decided to get rid of them before things started to fall apart. Even the power supply had way more complexity than any before or after that series, making aftermarket replacements a more complex search.
Just last week I picked up my first 68k ‘Book since I sold the 540c a few years back. It’s a PowerBook 165c. Like has already been mentioned, decided to go for it due to price ($30), super simple power supply (compared to 500 series), simple easy to repair batteries, and supposed ease of disassembly and repair. I got lucky that mine came with the RAM maxed at 14MB.
I’d be open to a PowerBook 180c though. No doubt the display would be way better quality than the 165c panel (if the 520c vs 540c is any good indicator). And pretty sure my RAM could be transferred between the two computers.
So for authentic, neat factor I’d say best is 180c, followed by 165c or any of the passive matrix grayscale models. Due to tunnel vision issue I personally wouldn’t take an active matrix grayscale 100 series unless it’s free.
However, for most capable, I’d agree with someone else in this thread that mentioned the 190cs WITH the 5300c display swap. Assuming you can find one with decent condition plastics.