Correct me if I'm mistaken but isn't Kid Buu (the tue majin buu form) the strongest of them all ?
Since you, Sianth, are saying that Super Buu is stronger because it has others absorbed ...
I always tought Kis Buu was the strongest not because it was his true form but because it was the form which he could use his full power with no restriction (that were given after he first learned how to absorb others).