The following are drawn from various sources, but mostly from "Physics" by Robert Hutchins, published for the University of Bath by Thomas Nelson and Sons Ltd. I use this not because it is necessarily the most up to date - it was published in 1991 - but rather because it is the most convinient for me, as it's the one I teach A Level Physics from in work. If you have any more accurate values, and you are one of those folks who can't bear to see his numbers correct to less than 50 decimal places, you can e-mail corrections if you feel you must..
Quantity Symbol
Value
Unit
Speed of light in vacuum
c
2.998 x 108
ms-1
Electron rest mass
me
9.110 x 10-31
kg
Neutron rest mass
mn
1.675 x 10-27
kg
Proton rest mass
mp
1.673 x 10-27
kg
Atomic mass unit
u
1.661 x 10-27
kg
Energy equivalence of atomic mass unit
1.493 x 1010
931.902
J
MeV
Mass of Earth
5.974 x 1024
kg
Mass of Sol
1.989 x 1030
kg
Power output of Sol
3.9 x 1026
W
Power intensity recieved at Earth due to Sol
1,386.729
Wm-2
Mean distance between Earth and Sol
1.496 x 1011
m
Astronomical Unit
AU
1.5 x 1011
m
Standard year
31,557,600
s
Light year
9.461 x 1015
m
Parsec
3.2616
light years
Density of neutronium (approximate)
1016
kgm-3