First of all, some companies will not be organized enough to keep track of the fact that you once applied to be an intern there. There's a decent chance that they won't even remember you.
Second, if they do interview you and ask why you rejected the opportunity to work there as an intern you can honestly reply that you wanted to explore other options at the time, but that as a recent graduate you are interested in employment with them.
They may push and probe as to why that is, in which case avoid comparing companies A and B. Instead, focus on why company A is a great choice for you, and how you would enhance their team.
manpreet
Best Answer
2 years ago
I am now a senior applying to jobs full time in industry X.
Last summer, companies A and B offered me internships. I went with B but realized, in the end, A probably would have been a better fit. So I am applying to A full time.
EDIT: The recruiter is a campus recruiter with that many campuses, so I am fairly (60%) sure he would remember me. I am not sure if this changes anything.