What is Your Favorite Engine?

[SlabGizor117]

I like the mainsail, it's a good all around 2.5m engine.

[el_coyoto]

It's kinda for me hard to pick one favorite engine, because I tend to choose them using !!science!! for a given mission profile, payload and TWR. For example, I enjoy the raw power of the Mammoth, but will use it only when it makes sense (lofting bigS rockets to space). I love unlocking the Rapier, because I know that it will simplify construction of my spaceplanes, etc...

Still, deep space engines like the LV-909, the Spark (although nerfed) or the NERVA hold a special place in my heart, because of they took my various space programs to many places. And back!
(I rarely use the ion engine because of the additional planning they require, and when I do, it's mostly always on non critical missions, like scan sat probes)

[monophonic]

T30: First available, and a cluster of seven gives a Mainsail a run for it's money. In fact I never use a Mainsail, as I find the Twin Boar superior and they are in the same tech node.

Mk55: Can add nice oomph to a 1.25m stack when you really need it. Also makes for a great zero-length sustainer engine, which allows me to fit longer stacks under the early VAB/pad limits.

[Wjolcz]

Juno. It's a cute engine and reminds me of Me 262.

[LeuZ]

The F-1. 

[superstrijder15]

I forgot the name, but I love the 1.25 engine you unlock last, in the very last node. for 2.5 m I'l go with my custom-made 4 cluster of the 1.25 one, and lastly and mostly used for 3.75: A custom-made cluster of 13 of those engines! Lifts everything, or at least close

[KerikBalm]

11 hours ago, HebaruSan said:

Top-tier vacuum I_sp in a jumbo size? Yes, please!

same here, I love that engine.

Its finding its way into the majority of my missions now as I currently have three of these in kerbin's SOI as ejector stages for my missions:

The LV-N is nice to... and is what allows the stage to stay in kerbin's SOI rather than going heliocentric and taking decades to recover/refuel and reuse

When you need to do over a thousand m/s burn at perapsis (even with a PE kick to get Ap past Mun), you want good TWR and a decent Isp...

And that... is the KR-2L

[mrclucks]

Stock, I love the Skipper.  Once it's 20km, it doesn't matter if it's roughly .80 twr, the ISP make it worth it to have to go a bit more straight up to keep it from falling down.  I also usually use it for civilization burns for kerbin/burn to go interplanetary or to minmus/mun. 

 

Modded, I love the single nozzle vacuum engine in spacey.  Combined with tweakscale, it almost always beats the terrier and poodle for DV if I scale it appropriately.  I know it's cheating, but 1500m/s DV vs 4000m/s DV is hands down no choice, regardless of the extra weight.  

[Jetski]

Mainsail with Kickbacks to get me to orbit, and nothing but NERVAs from there on out...

[Willbl3pic]

I love the Terrier (LV-909), the Aerospike and the Vector!

[klesh]

The 48-7S "Spark" engine is my fav.  I prefer to make things as small as possible.

Edited April 22, 2016 by klesh

[max_creative]

Bigger is better. 

[Raideur Ng]

Skipper. Perfect for all your medium lifting needs.

[Kerbinchaser]

The Kerbodyne "Rhino." Insane amounts of thrust and gimbal, and when used as a transfer stage, it works great. 

Edited April 23, 2016 by Lo Var Lachland
punctuation change