Season 1 of Ds9 is much better then say, season 1 of Babylon 5. And Season 2 of Deep Space nine is a very good season. The best would be to watch them all, but if you Insisted on skipping episodes.
Season 1
Emissary
Past Prolog (so you understand some of the Bajorian angles)
Babel (Good episode, and reminds you that there is still booby traps about)
The Negas (So you understand the Ferengi epsiodes)
The Forsaken (Important for later episodes, even if its meh)
Duet (MUST watch, could be argued that it is the best of what DS9 can do)
In the hands of the prophets - Season final, must watch.
No reason to skip season 2, as even the weak episodes generally have fans and strong points. A big thing to remember is that DS9 thrives on characters interacting, and not all the time LIKING each other. In fact, Bashir and O'brian dislike each other at first, but in a natural progression they become great friends, Outside of season 1, I only found that ds9 has one Bad episode a season, which is rare.