Here are the patterns I could think of, represented by their unit cells and with their densities listed beside:
![1/5 hexagon tilings](https://cdn.statically.io/img/i.sstatic.net/IVFIo.png)
The first tiling shown in the question has no code in my diagram and has density $\frac{46}{49}=0.9388$. This is not very interesting because it is a rearrangement of the A0 tiling (the second in the question), which has the same density.
From the A0 tiling we can shift the hexagons on their long edges by one to five units to create the A1 to A5 tilings. As the holes between the tiles grow, so does the density decrease:
- A1 has density $\frac{23}{26}=0.8846$
- A2 has density $\frac{46}{61}=0.7541$
- A3 has density $\frac{23}{38}=0.6053$
- A4 has density $\frac{46}{97}=0.4742$
- A5 has density $\frac{23}{62}=0.3710$
The B tiling is the last one shown in the question and has density $\frac{23}{27}=0.8519$.
Now to answer the question of densest possible tiling. When I started typing this I thought it was tiling M, which has density $\frac{23}{24}=0.9583$ and features rows of tiles that can slide over each other.
![Tiling M](https://cdn.statically.io/img/i.sstatic.net/8U5Is.png)
Then I realised the rows could be pushed into each other a bit more, resulting in the real winner: tiling N with density $\frac{46}{47}=0.9787$.
![Tiling N](https://cdn.statically.io/img/i.sstatic.net/0t9OK.png)
So if you want to tile a real wall or floor with this shape, your best bets are tilings M and N. While M is less dense, it isn't chiral like N, and its rows may make it better suited to the (usually) rectangular areas tiles are supposed to cover.