The B'rel Class Bird-of-Prey tbh. It's been around forever, same as the D7 Class Klingon vessels.

It's also why I have a B'Rel Class Bird-of-Prey on my Klingon, because I love it O_O

The B'rel/K'vort class Birds of Prey are pretty much the most Iconic as they are seen the most out of most of the Klingon Classes. The D7/K'tinga are icons as well but their own appearances tend to be rather lackluster unlike the as forementioned 'Hero' Birds of Prey.
The Vorcha on the other hand had the least amount of hero time only having that status (briefly) as the IKS Bortas, all other ships of the line were red shirts so to speak in the dominion war.

Some great information here, especially about the "Bird-of-Prey" being originally a stolen Romulan ship.

I got inspired by this discussion and spent some time reading about the Klingon ships, including 'behind-the-scenes' reasons for their designs. The info is mostly from hobby modellers who are passionate about the Klingon ships.

I might surprise some of you with what I've found out, considering that I just started getting into Klingons, and haven't really been much into Star Trek. I'd like some 'hardcore' trek fans to either confirm or deny the following, please:

Apparently, the Vor'Cha class ship was originally designed as a symbol of the alliance between the Klingons and Starfleet/Federation. Due to that, its 'nacelles' are Starfleet technology and look very similar in design and color to TNG's Enterprise 'nacelles'. I wasn't able to find what Klingon technology Starfleet/Federation incorporated into their ships in return, at least the visible kind.

According to the information I've found, there were never meant to be any Klingon ships with Starfleet/Federation 'nacelles' beyond the Vor'Cha. The Negh'Var was originally meant to be a completely different design but the designers were told that the schedule for the episode where it first appeared has changed, and that they needed to come up with something quick. As a result, they built the Negh'Var literally on top of Vor'Cha by adding parts to it. That's how the Negh'Var retained the Starfleet/Federation 'nacelles'.

The original Klingon technology had a cyan or blue-green color for their 'nacelles' and a different glow to them.

I have to say that even though I'm too young to be nostalgic about the early D7 K'Tinga ships, I really like their strong appearance. If one thinks about it, they originally had to come up with a Klingon ship that instilled fear into Starfleet, and D7 is what they came up with. I like it!

only for the children who grew up thinking TNG was the peak of the Star Trek universe. (IMHO DS9 by far outshone TNG)

oh, and by the way, both Voyager and especially DS9 played Homage to TOS, and TNG directly ripped off a TOS Episode..

I go by with what's shown in the movies and TV shows. Everything else is optional fluff, IMO. Some good, some bad stuff out there.

That being said, nacelles with Klingon warship designs aren't anything new. The D7 had them in TOS. The remodelled version, the K'Tinga had them. Versions of the cruiser shown in TMP timeframe movies, namely Undiscovered Country, had some "glowies" on the nacelles already such as found on the "Kronos One," before glowing ships became all the rage with TNG.

B'rel BoP. I can respect the K'tinga as the TOS Klingon ship, and it showed up all the other series in some form or another, but TOS was canceled a decade before I was born and by the time I was old enough to watch reruns even then I recognized how dated it was. The B'rel on the other hand had staring roles in 5 movies and was THE Klingon ship for TNG and DS9 (moreso than the Vorcha, IMO), as well as popular with the likes of Ferengi pirates and a certain privateer named Dukat. Its like the AK47 of the Trek verse; even over a century old and with no logistical support it just does everything. I would not be surprised if in that famous future battle with the Sphere Builders and the Enterprise J, there's still B'rels or K'vorts around.

The D7 is the very original design of Klingons. However, there was a cooperation between the Romulan and the Klingon empire during which the Romulans passed the cloaking technology to the Klingons and in exchange to the Klingon D7 schematics (I think, the romulan were also limited in their capacity of warp drives up to this time).

I think during this time, the B'rel Bird of Prey might be designed (it clearly shows some Romulan features), becoming one of the most iconic ships of the Klingon empire.

Though the D7 might be more original "Klingon" in its design, the B'rel bird of prey is more iconic ship, because more important Klingon antagonists (like Captain Klaa or General Chang, the Duras sisters) have used it in later mobies and series.

I prefer DS9 as well but tthat doesn't change the fact that TNG is the peak of Star Treks popularity. You can fanboy it up all you want but that's not going to change anything.

Also, those "children" are in there 30s now.

BoPs, and you know what, I want more of them, doesn't even have to have fancy consoles, different stat layout to the Heavy BoP, just a new skin...

Never been this close.