SWTOR (Star Wars The Old Republic) has datacrons which are fun in a PiA way to get as they add to your stats, and you can make a relic which is useful.
Here are different links to them.
SWTOR-spy.com is my favorite for the walk-thrus. I waited until 50 to start going back and getting them, as I was always thrilled to stumble across them out in the world.
I lost the thread on the datacron locations, so starting one with a variety of links.
Walk-thru on Swtor-spy.com: http://www.swtor-spy.com/datacrons/
** I've been told some of the locations were incorrect, but I haven't had issue with the walk-thrus
List of ALL datacrons (by codex #): http://swtor.wikia.com/wiki/Datacron_Locations
** You can check your Codex #'s to see which you have/haven't done
Datacron - mixing shards: http://swtor.wikia.com/wiki/Datacron
>>Matrix Cubes function as relic-type items, and are equipped as a part of
the player's gear that grants a passive stat boost. Depending on the
color combination, the Matrix Cube will give a different statistic boost
and will also vary in level requirement. The level requirement has no
relation to the current level of the player assembling the cube, but
rather the colors of the three shards. There are four tiers of cubes at
levels 15, 24, 32, 50 .
Though it's not always the case, usually the more of a single color
shard in a cube the higher level it is. Therefore a cube made with Red,
Blue, and Yellow, some of the first colors acquirable, you will have a
very low-level cube.
Other location sites: