Since this is something I wanted to be sure about, I went and actually calculated how much everything is worth by using awesome power of science. Turned out I was initially wrong about one value. (Shady and others were also wrong.)

This is how you do it: let's say submission gives you x_s exp, view gives you x_v exp, etc. Now, if you know how much of everything some person has and you also know how much exp they have, this gives you a single liner equation with 6 unknown variables which looks something like this:

x_subm*a_subm + x_views*a_views + x_diam*a_diam + x_comm*a_comm + x_favs*a_favs + x_dwnlds*a_dwnlds = exp_total.

Now you collect data. You go to profiles of some poor, unsuspecting people and record how much of everything they have. Now you got yourself a system of linear equations. This is the data I collected:

2 142 6 8 0 17 197
1 299 4 4 0 0 323
3 189 10 17 1 28 286
7 839 20 7 0 75 1021
3 148 4 2 1 39 211
1 65 2 3 1 0 80
6 786 8 8 5 129 973
2 3971 74 70 23 336 4793
15 11859 144 182 21 106 12909

You process these numbers - you plug them into an on-line linear regression solver. The solver spits out the values that you wanted to know. Try it.
This is what is says:

Submission gives 0.
View gives 1.
Diamond gives 5.
Comment gives 1.
Fav gives 2.
Download gives 1.

(I was wrong in thinking that a fav gives 1 instead of 2, shady was wrong in thinking that a comment gives 2 and a submission 5, instead of 1 and 0.)

This