Help aquascaping my 20 long

First one

I would just use the one piece. Move it closer to the center, but not perfectly centered. Still off to one side a bit.
It is so large it already dominates the tank.

In the third pic, the standing up wood makes a nice tree effect.

I like the second one the best, actually.

Third one. Strap some moss on the DW and a few foreground/background plants in there and call it a day

I like the second one if the piece on the right were completely removed. Both pieces is too much, but just my opinion.

Second one.

Alright so far it looks like number 2 is the most popular. If I do remove the right side piece should I just leave it open? Put a large bunch of background plants? Or maybe a small pile of river rock? I am planning on including a pair of rams or apistos in this tank so they may like the rock.

I like the first and the third. They make tunnels and their position makes them look like they are one piece

I like the first one so far. It has a nice flow. I need to redo my 20long. I think I will go with larger wood like you did.

first or fifth (last one) I really do like the left side also

Try a few placings of just the one branch that is on the left in these pictures.
Move it somewhat closer to the center.

Look at how heavy it looks, the thick end needs to be closer to the center, the thinner end needs to be away from the center. Sort of like children on a teeter totter. The heavy child closer to the center, though not right at the center, and the lighter child away from the center.

Thank you all for the replies! I should probably mention that in the first and third, the right side is set back from the left and forms about a two inch channel between pieces. It is hard to see from the pictures.
I will definitely be sliding the left piece slightly more toward center but still off-center.