Both aikido and hapkido are primarily descended from Daito-ryu aikijujutsu - aikido having other Japanese influences and hapkido drawing a lot of kicks and strikes from Korean influences. The philosophical component of aikido is not present in hapkido, so there's no emphasis in sparing your attacker unnecessary injury, therefore it teaches a lot of strikes, breaks, etc.
Some from wikipedia:
Although aikido and hapkido are believed by many to share a common history, they remain separate and distinct from one another. They differ significantly in philosophy, range of responses and manner of executing techniques. The fact that they share the same original Chinese characters, despite 合 being pronounced "ai" in Japanese and "hap" in Korean, has proved problematic in promoting the art internationally as a discipline with its own set of unique characteristics differing from those of the Japanese art.
Whether or not aikido's right for you is just personal preference. Just try them both and see what you like best.