25-26 is my ideal age to get married, but eh if it doesnt happen by then i dont really mind. Its all good.
I'm 24 and have been together with my boyfriend for 5 years now, if he decided getting married would be on the cards next year, I would freak out like you wouldn't believe (then again I am probably not going to get married and if I did it would only be for any government legality/benefit, because for me I don't see the point in it otherwise). We both freaked out when his good friend got married last year (his friend was 25 when he got married). However judging by people on my fb list, 23-25 seems to be the age people are doing the marriage thing.
I still think it's rather young at this age. I guess it depends on your life as well. If you've finished studying by the time your 20-21, then have worked for 3 years full time, then I guess you feel you're more mature and adult to handle it. *shrugs*