I liked Netscape 2 and 3. Netscape 4 was a bit bloated and had some very questionable interface design. I switched to iCab as soon as it came out and used it until I moved to OS X.
In a related matter, iCab 4 was recently released. The first version seems a bit buggy (especially with text fields), but I have high hopes. The new rendering engine is fast and accurate. I never would have stopped using it except that the rendering engine fell behind the times; version 2 didn't support CSS well, and version 3 was very slow. If the bugs are ironed out in version 4, I'll switch in a heartbeat. iCab puts everything else to shame in terms of features and interface. Heck, iCab from 5 years ago puts most modern browsers to shame. Man I miss iCab. I look forward to the day when I can use it as my primary browser again.