I use BdoublesO's Texture pack. I like it because it tries to stay close to the default looks while changing only a few blocks to something completely different. Its also adds an extra variety of blocks to stone bricks, polished andesite, stone, Exct... Use this with optinfine and the sky change makes it even better for certain biomes. I took some screenshots of /warp HoboCapitol and HoboVillage for you to look at. Links: Version 1.12- https://goo.gl/Z7hXKW Glazed Terracotta add-on- https://goo.gl/dihxmz Youtube video- Spoiler: Screenshots
If you cant decide on any resource pack that makes the game look different, i'd suggest Faithful resource pack. It's basically the default pack with better resolution.
I suggest you become acquainted with the new Minecaft textures that will be coming in a later update (probably not 1.13 but sometime down the line). These will become the new standard for Vanilla, and my opinion is that they are not as different as people make them out to be. Just takes a little getting used to. Here is the link on the official Minecraft website. https://minecraft.net/en-us/article/try-new-minecraft-java-textures
