FVWM was the window manager when I did a "startx" for the first time on a linux box. and I loved the MWM look alike mode from day one.
Over the years.. I have tried a lot of other window managers... but eventually came back to FVWM...
Between Dec. 1999 - Feb 2000 I was using Gnome with a whole bunch of applets and buttonbars with Enlightenment as the Window Manager(used the brushed metal theme by TigerT)
But when I returned back to India in Feb 2000 I was forced to use a PII-200Mhz(??) for a few months.. and there wasn't much of a choice but to return to FVWM.. and during those months I made some customisations to fvwm for the first time... and then I got so used to the configuration that even when I got myself a P3-733 in Oct. 2000 I continued using FVWM.
(July, 2002) I'm currently using the devel version of fvwm .. couldn't wait till until the stable release to try out the latest featues(Transparency/Translucency rocks!)