If each species of Star Trek gathered with their best ship and fought it out, who would be victorious? Rules: No alliances and no Q.
The Ferengi. They'd be the only ones smart enough to run away from the suicide that is a free for all.
The Federation, they would just use they timeship (Wells class USS Relativity) to travel in time to snure that there wouldn't be any other ships there.
I'm torn between the Borg and their tactical cube, The Jem'hadar and their planetary assault carrier, the Krenim's time ship, Species 8472's bio ship, and the Vulcan's red matter ship (funny that one of the most peaceful races like the Vulcans have one of the most destructive weapons, even though it was built for peace).
^Also Voyagers enhanced ship from the last episode but would it be able to stand against the Crinum's time ship? They could adapt to it but only after it's used. The adaptation before was lost after Voyager beat the Crinum before.
I'm assuming that this only includes species which we've actually seen piloting ships. I'd say the Douwd, if we include his hologram ship from "The Survivors." I think that ship could take as much energy as the Douwd could, and I doubt any starship could produce that. If the Douwd isn't included, I think the Krenim, Species 8472, Kelvans, and Tosk would be some of the hardest to defeat. Possibly the Borg also.
After thinking about it, each species has their strong points over another species. 8472 beats Borg Hirogen beats 8472 Humans beat Hirogen Borg beats Human... Maybe there is no dominant species in Star Trek.