In Titanfall, do the different Titans have weak points that are better to shoot at? If so, are they the same on the different chassis?
They do have weak points... but hitting them at their weak points will deal extra damage only if their shields are depleted.
The titan's weak spots will be highlighted red when their shields are depleted. Each titan is different so naturally the red weak points on each of the titans will be on different locations.
Then of course, there is the option to jump onto a titan as a pilot to rodeo and attack them directly bypassing their shields. Of course, take caution going this route because you will be left very vulnerable when attacking a titan this way. There are ways to defend against rodeoing pilots so look out when attacking a titan this way.