Which algorithm is generally considered to be more secure, and is AES-192/AES-256 still considered to be secure?
After reading this it's lead me to belive that the Rijndael algorithm would be a more secure choice, but is this actually true?
It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center.If this question can be reworded to fit the rules in the help center, please edit the question.
AES is a subset of Rijndael (FIPS-197). It's still being considered secure, if you continue reading to the bottom of the article:
The attack you suggested is called a biclique attack and is slightly faster than it would take to bruteforce an AES key. Considering that would still be a a few trillion years it's not really feasable.
Also this is the official press release from the Katholieke Universiteit Leuven about the code being broken. (This is the university where both AES and the attack against it were made)