Yup.  What are your favorite object or objects in the FC2 editor?

Mine would have to be: . . .

(1) Concrete Blocks. Yup, all of them. I think I over-used these a bit on my earlier maps, but I've been trying to add a bit of variety as of late. Still love 'em though. They cause amost no drop in performance no matter how many you use.

(2) Jackal Berry Tree 01. The low, wide ones.  I like greenery in my maps, and I particularly like this shade of green too. They work well for making a complete natural canopy. (See my "FLS Stoic" map.)

(2) Woodland Large Rock 02 (I think). The rock that has very straight edges and flat sides. I use them all the time to line the edges of various structures that I want fitted along some rocks. This rock shape also come in the desert pattern too I think... A bonus is that they only cost 48 memory to place as well.

1. GREENHOUSES!
2. GREENHOUSES!
3. GREENHOUSES!
....

20. Palm trees
21. Concrete platforms
22. Ammo Piles

I think the Greenhouse fact is self-explanatory: They simply look cool and give your map a glass effect if used right.
If you want to create something entirely covered by glass, greenhouses would be your best choice. Best examples would be malls or skyscrapers.
They can even make a fucked up prison building look cool. And and and.... The list could go on without an end.

As for the Palm trees: They also look cool.

The concrete platforms on the other hand, they're on my list because of their high usability - Some of my map structures entirely consist of them (+greenhouses and details).

Why ammo piles? 'Cause of the parachute glitch!  

I personally like the large gray platform.  I believe it's platform02.

I do like the greenhouses used as walls though.  It's a nice touch to the border of almost any map.

Platform 3 - quite large, very versatile, and cheap.

Colonial fencing (all) - the only true plain(ish) building block - I couldn't make maps without these.

Jungle collection (all) - best way to naturalize terrain imo - looks great.

You did mean "many" right?  Not "man"?
Because that's pretty funny that you mentioned the pipe piece.

i like platform 3 i flip it over then use it for buildings im makeing a map wich will only be on the roofs im also planing to make a rainforest i aint going 2 place trees and bushes like some noob ima do it proply