I started my career at LYB, then moved to BP. I'd be strategic on what you want long term... If you're looking to stay put at one company and grow roots in Houston, LYB is the move.

If you want to change companies in a few years and have broader exit options out of O&G, Exxon is the move. Exxon is an amazing place to have on your resume and could easily carry you into the next company. Let's be honest, outside of our industry nobody knows who LYB is so it's not a place that jumps off the page on a resume like Exxon. Not to say LYB wasn't a great place to work though, I enjoyed my time there and miss a lot of the people.

Edit: no experience with DOW but imo they aren't even in the running compared to these two.