Zoom lens: 70-200 f4 L IS, I agree!
Prime lens: Likely the 24 TS-E. I am sure the vers. II is even better, but I come well along with the old version, too. Bought it used, the copy is from the early 90's, but the photos with it are stunning. I became a big tilt/shift fan by using it!
Oh, I suppose I have to say the 300/2.8 L IS II. Each lens has its own strengths and uses, but for optical excellence, build quality, and AF performance, I don't have many that rival the 300. Closest might be the 135 L - amazing for the cost, but its perceived build quality is just a notch lower. Probably good because the light weight is part of its charm.
Surprisingly according to my usage charts my worst,the 17-40 sees far more usage then my L primes combined,followed by the 70-200/4 L,then the 70-200/2.8 L and then the 28-70/2.8 L.The 400/5.6 sees the most use of my long lenses,followed by the 300/4 and then the 600/4.
The ZE 21/2.8 sees the most usage of my manual focus lenses followed by the Nikkor 300/2.8 and then the Nikkor 200/2.
I didn't want to believe the hype about the thing, but then I picked one up found myself selling multiple lenses which weren't getting used anymore because of it. (135L, 100-400L, 70-200 f/4). Good for racetracks, good with TC's, good for photo shoots with my daughter, good wide open, good stopped down.
One of two lenses I could never see selling (other being the 35L).
Got a very close call between the 135L and the 180L.
Why not the 180L?
1-The 180L has an incredible rendering when used for portraits too and the only thing that avoided me from keeping it instead of the 135L is the lack of IS.
******************************Why the 135L?************************************
1-Small and light and razor sharp pictures.
2-Great subject isolation
3-Fantastic AF speed and very precise even with my 5D
4-Magic pictures
5-Not so expensive as other L lens.
6-Minimum focus distance is perfect for floral pictures
7-It takes 1.4 extender very well
8-On full frame is great for outdoor portraits
9-On crop 1.6/1.3 and FF is great for indoor sports
10-It is not white.
