Yes, you could justify being any alignment other than Chaotic Neutral. How you do it is based on the story you want to tell about your character.
First figure out who this Rogue is, beyond just someone who steals, and then figure out what alignment best fits this Rogue.
- Your class does not define your alignment.
- Even a broad play style, as you described (steal what you can for yourself) need not define your alignment, though it can inform how your DM adjudicates your alignment to the extent that he cares about it.
- You can easily justify Neutral Evil, Chaotic Evil, Chaotic Good, and Neutral, even Lawful Evil, as a grabby Rogue just using the outlines in the Basic Rules.
Summarized from the Basic Rules pp. 33 & 34 (Same language in PHB).
A typical creature in the worlds of Dungeons & Dragons has an alignment, which broadly describes its moral and personal attitudes.
Individuals might vary significantly from that typical behavior, and few people are perfectly and consistently faithful to the precepts of their alignment.
Chaotic good (CG) creatures act as their conscience directs, with little regard for what others expect.
Neutral (N) is the alignment of those who prefer to steer clear of moral questions and don’t take sides, doing what seems best at the time.
Lawful evil (LE) creatures methodically take what they want, within the limits of a code of tradition, loyalty, or order.
Neutral evil (NE) is the alignment of those who do whatever they can get away with, without compassion or qualms.
LE Rogue: either a member of a Thieve's Guild, or a Thief who was taught a particular moral code as a youngster, and steals based on that ethos. Since you have not fleshed out this character beyond a single sentence description in your question, you can easily fold in a "look out for number one" attitude and then lay detailed plans for each theft because you are loyal to:
- Your family name
- Never being poor again
Your Guild encourages maxing out the take, and you keep just a bit off the top for yourself because you've seen what happens to rogues who lose their touch ... no pension plan!
Summary: flesh out who this character some more, and you can make it LE with little trouble.
NE Rogue: do whatever they can get away with, without compassion or qualms. Almost perfectly described your short summary right there.
N Rogue: seems like a good idea at this time to steal that loaf of bread, I'm hungry. Rinse and repeat for any temptation to steal.
- CG Rogue: takes things because it's an old habit from stealing food to survive on the mean streets of Luskan, but gets a crushing case of conscience (Mom would not be proud of me, Dad would roll over in his grave) and then either returns it or donates it to a worthy cause. That is a step toward your CG.
- CE Rogue: you not only take whatever you want whenever you want to, you get a kick out of stealing from the handicapped and stick a shiv into anyone who gets in the way.
So how does that help me with creating this Rogue?
The point of the above amplification is that you need to flesh out who this rogue is in much more detail than a simple alignment description.
Once you know who this Rogue is, you then figure out what alignment will fit that Rogue best. The PHB has a set of tables at the end of the Backgrounds sections that provides more character flaws, ideals, traits, and bonds to help you add depth to "Rogue/Thief, of some alignment."
Your own imagination does the rest.
While you are at it, you need to fit your rogue to the Campaign setting you are in. Talk to your DM about that part of your character development.
Alignment by itself offers insufficient depth for your character.
As a last thought, why be a "typical Rogue/Thief" in the first place? Be unique.