based on the options you presented, i would say your be bet would be aikido. however, there are many different levels of quality within each of the arts you listed. i have to admit, i'm biased toward the internal end of the martial arts spectrum. i've been studying tai chi (chen-style taijiquan) since my early 20's. i can say, had i not started with tai chi, i most certainly would have studied aikido.
aikido's founder, morihei ueshiba, was a brilliant fighter and beautiful human being. there is a strong spiritual component to good aikido, and it is a pretty intense workout. you will find a great deal of cardio and flexibilty training integrated in these studies.
it is difficult to find a good tai chi (taiji) class. most classes i've seen are SEVERELY watered-down, westernized, new-agey programs far removed from tai chi's martial roots. avoid any class that tells you that tai chi is not a martial art; they have no idea what they are talking about. if you do find one, make sure it is one of the primary family styles (chen, yang, wu, sun, wu-hao), and if they don't know, don't go. make sure they extensively cover the qigong aspect. if they don't, don't waste your time.
i can't really speak for the other options you listed; i don't have any significant experience with them. again, bear in mind that my opinion is biased toward the internal end of the martial arts spectrum. good luck in your search. may you find the perfect art for you.