|Saitou Hajime is one of the most interesting guys in Rurouni Kenshin (after Kenshin and Aoshi, of course ), but he definitely is an archrival to Kenshin and could possibly match Kenshin in strength. He, like Kenshin, upheld his belief when it comes to the bad guys, though he uses a more harsher judgement than Kenshin.
I love how he always put down Sano, but I bet deep down he respects Sano a lot.
I almost couldn't believe that he is
Spoiler (mouse over to view)
married, though his wife was never shown in the manga. maybe he's just joking?