Using Lubuntu right now but it seems unstable, anyone know if Centos or Debian is better to run with FF on a 1GB ram vps?
LXLE could be a good choice, its basicly based on debian / lubuntu.
Its very leight weight with LXDE desktop, and pretty feuture packed.
Also the recently released Rosa R6 LXQT version is very leightweight aswell.
Its based of Mandriva.
What was your experience that led you to the conclusion that Lubuntu is unstable? (Asking because I've had the exact opposite experience).
As far as I've tested LXLE uses a smidge more RAM than Lubuntu. But I have not tinkered with the low-RAM version of it.
Out of curiosity: What are you trying to do with that VPS/FF combo?
If you give us a clearer idea of what you want to do we can give some good answers. As 'lightweight' to me could mean you want as minimal resources as possible in which case your best options would be any distro with openbox and a minimal browser like uzbl or similar.
Before you wipe Ubuntu off maybe try it with Fluxbox or something, its very very lightweight and will do what you're wanting. Take a look here for details and instructions