I am a member of Fitness First and was a member of California
Fitness before.
This is what I think.
1. Both are out to get as much membership sales as possible. After
you join, they will then try to get you to sign up with a personal
trainer. A session with a personal trainer works out at between $75
to $100 depending on how much they suck you in for.
2. Gym classes like yoga, dance, aerobics are about the same for
both.
3. "Good" things about FF over California.
a) The smaller locations will give you towel, t shirt and shorts to
use for gym. You cant keep them of course- you hand in your
membership card while u wear the stuff and get it back when u
return your locker key.
b) FF provide lockers with locks. At California, you have to
provide your own padlocks. If you forget, you can buy one for
$5.00. I personally hate this. I have bought 3 padlocks from them
because of this.
c) Bathrooms are quite nice. Marble, carpet, deoderant, talcom
powder, soap.
d) Provide drinks and cups- you get it from a dispensor like u see
from McDonalds and BK. Is "free".
e) Some FF places like Capital Towers opp Tanjong Pagar have
swimming pool too. The shorts provided can be used as swimmers I
think.
f) Can hire movies on VCD at no charge once you are member. From
memory, they have quite a range, though it isnt kept up to the
minute.
4. "Good" things about California over FF.
a) Seem to have larger gyms, so more room and equipment.
b) Opening times seem to be slightly longer- ie the close
later.
c) The cardio machines, like treadmill and stationary bicycle, have
built in fans which you can point at your face to cool you down. FF
ones dont. I like the fans.
But regardless which gym you choose, the main thing is to know how
to use the machines there and be disciplined.
If you dont, then it is a waste of time.
They offer a free one session with fitness trainer. If you are new
to the machines, then you wont believe how much you dont know about
using them.
Just dont get sucked in unless you really want to get a trainer
too.
I hope this helps 
Cheers!
