Which existing block or item texture do you think should be improved?

Sure, there are texture/resource packs, but pertaining to standard Minecraft texture, what do you think should be improved?

Starting with items, I'd like to see Lapis Lazuli and Tripwire Hooks have their textures updated. To me, I've always thought Lapis Lazuli looked like raisins and Tripwire Hooks looked like keys.

With blocks, I would say Glass Blocks and Sponge Blocks. The streak of lines in the middle of glass blocks always looked awkward to me, and I think it would be nice if they had a low opacity, so that glass actually looked more like glass; it would also give better visibility when players look outside from glass blocks. As for sponge blocks, I think they could have larger pores instead of the small ones they currently have.

 

This one's more of a preference, but I don't like the looks of Glowstone Blocks. They're so useful (for lighting up the area), but they look terrible. I prefer the design of Redstone Lamps more, but the inconvenience is that you need to power it with redstone, which can be inconvenient at times.