My personal favorite for 68k Macs has long been the AudioVision display -- decent ergonomics, great inbuilt speakers, really sharp picture, and of course, an ADB hub. Just about the only thing it doesn't bring up to your desk from the back of your Mac is a serial port.
After that I had an Apple Multiple Scan 1705 for awhile, great solid display, and it would've worked with a VGA computer too, but I had to leave it behind last time my family moved.
Beyond that, I love Dell UltraSharps, and want a 1708, 1800 or 15xx series, and I also would love one of the original 15-inch Studio Display LCDs.
The original Studio Display is, indeed, awesome. Sadly, mine is a little busted at the moment. :-(
Yup, that is the entire line of 15" Studio DIsplays. At left is the ADC model, in the middle-back is the Blue & White VGA model, on the right is the graphite DVI model; and in front is the original dark-blue/gray old-Apple DB15 model. Looks right at home next to a beige G3 tower. You can also see the massive brightness difference between the models. The B&W one really is that dim. My original one will power up (LED comes on, and I can hear slight e-buzz,) but the backlight doesn't come on, and the screen doesn't seem to get any signal.
I have one more B&W one, but it is flaky, losing video after a few minutes. Finally, for the four 'original' style ones, I only have two power bricks. (I tried hacking a PowerBook 5300 power brick, since it supplies the same voltage and amperage, but I was unsuccessful.)
Edit: I also like my ViewSonic 21" CRT with BNC inputs. I have a BNC-to-Apple-DB15 cable, and the picture is just rock solid, even at 1600x1200 or higher. The monitor was an ultra-high-end one in its day, doing 1600x1200 at 85 Hz, and can be pushed out-of-spec all the way up to 2048x1536 at 60 Hz. I had my beige G3 running it at that with Mac OS 8.0 and AppleShare IP 6.0 Server. Lets me see *ALL* of the AppleShare windows simultaneously. One funny thing is that it will let you force it to 'unsupported' resolutions over BNC, but not over VGA.