1. A is completely / totally / entirely different from B.
2. A and B are different in some/every way / respect / aspect.
3. A and B differ in….
4. A differs from B in….
5. The difference between A and B is/lies in/exists in….
6. Compared with/In contrast to/Unlike A, B….
7. A…, on the other hand,/in contrast,/while/whereas B….
8. While it is generally believed that A …, I believe B….
9. Despite their similarities, A and B are also different.
10. Both A and B …. However, A…; on the other hand, B….
11. The most striking difference is that A…, while B…