Omet'iklan: I am First Omet'iklan, and I am dead. As of this moment, we are all dead. We go into battle to reclaim our lives. This, we do gladly, for we are Jem'Hadar. Remember - victory is life. Jem'Hadar: Victory is life.
Followed by a Starfleet version:
Miles O'Brien: I am Chief Miles Edward O'Brien, I am very much alive and intend to stay that way. Sisko: Amen, let's get it done!
Bad Liar: Odo, according to Weyoun. Being a self-professed expert in lies, he would know.
Blue and Orange Morality: When a Jem'Hadar Second (in command) gets in a fight with Worf, both are punished. However, the Omet'iklan kills his second as punishment, and calls Sisko weak for not killing Worf, who is confined to quarters when not on duty for the remainder of the mission. This also extends to other areas, as the episode serves to showcase the Jem'Hadar mentality.
Continuity Nod: The Iconian gateways reappear from the TNG episode, "Contagion." Worf later recalls his experience and what the Enterprise crew was forced to do.
Enemy Mine: The only time that Starfleet and the Dominion work together to defeat a mutual threat.
Expendable Clone: Weyoun (4) is killed in the very same episode that he is introduced in, but that's okay because the Vorta are all mass-produced clones.
Note that they later introduced the clone concept PURELY to bring back Weyoun, and, as such, at the time, the assumption was that Weyoun had been Killed Off for Real.
Jem'Hadar: How old are you? Jadzia: I stopped counting at 300. Jem'Hadar: You don't look it. Jadzia: Thank you.
The Profiler: According to Weyoun, Sisko's psychological profile is required reading for all Vorta.
Weyoun: I probably know things about you you don't know yourself!
Portal Door: The Iconian gateway connects to an instantanious Portal Network that had allowed the Iconians to rule an empire 200k years ago, so the danger of the Jem'Hadar getting control of it is even more pronounced as a result.
Serious Business: How the Jem'Hadar view the white distribution, much to Weyoun's annoyance.
Soldier vs. Warrior: The difference between Starfleet and the Jem'Hadar is defined here. The Jem'Hadar fight "to reclaim their lives," whereas Starfleet fights to obtain an objective.
Teeth-Clenched Teamwork: The Jem'Hadar and the Defiant crew are only united by the desire to wipe out the renegades and make it explicitly clear (More-so on the Jem'Hadar's side) that if they were not on this mission that they would kill the other side in a heartbeat.
This Is My Chair: When Bashir sits down in the mess hall, Dax and O'Brien warn him that he's sitting in Worf's favorite seat. Bashir is unimpressed—until Worf and his Death Glare show up.
Undying Loyalty: Omet'iklan tells Weyoun that the Jem'Hadar are more loyal to the Founders than the Vorta will ever be.
Unfriendly Fire: Omet'iklan shoots Weyoun for questioning the Jem'Hadar's loyalty to the Dominion.
Ungrateful Bastard: The Jem'Hadar are ready to kill Sisko and his crew for saving their lives. Weyoun has to order them not to.
Unspoken Plan Guarantee: The Starfleeters and the Jem'Hadar plan out and rehearse the operation step-by-step. As soon as they beam down to carry it out for real, things start going wrong, forcing them to improvise.
Video Wills: Dax and O'Brien record them. O'Brien hopes that Keiko and Molly don't end up hearing his.