I love so many of the characters -- all of the ones listed and so many of the ones not listed. But I ♥♥♥♥ Kira!
My fav was O'Brien, I could never get enough of him. I liked where the O'brien and Bashir buddy relationship was headed but hated, HATED the genetically enhanced Bashir addition.
DS9 was a near-perfect ensemble of great characters working together, so I can't really say "best". I will say a personal favorite is Nog, who should at least get the "most improved" award. In seven years he went from an illiterate pickpocket to a mature engineering lieutenant, so yes - I'll go with Nog.
Nog didn't have much depth, but his trials were understandable and desire to excel genuine. My son, 7 years old, who has just started liking the show, really relates to him.
My favourite DS9 character is Garak, but if we're just going with crewmembers then it would be Odo. Amazing character. Was a ridiculously tough decision though. They're all great characters and perfectly cast.
I love sisko,kira and quark the most out of the main characters so i voted sisko to make it a three way tie.
Member of the cast; Garak is my A #1 - of all trek too. For crew member I chose ODO, reminds me very much of my father. Have a great relationship with my Dad, and both Odo and my Dad share the same type of job. And my Dad's all about Justice like he is. Overall just amazing character. But honestly, everyone in DS9 was amazing, from the biggest characters to the more smaller ones. Even Damar kicked ass.
I picked Quark as my 'best' choice. He was a wild-card and stayed true to his character til the end.