Minecraft isn't a graphically impressive game. Its textures are low res and shaders are non-existant, but that's part of the style some people like. If you however, like your games beefed up and graphically impressive, you probably already have an HD texture pack installed. Here are some mods you should check out to make Minecraft look even better.
Optifine is a very high profile mod. Almost everyone knows about it, and it's popular for a reason. It's a combination of various graphical and performance improvements. Optifine not only raises your framerate drastically, but it also adds several neat effects to make Minecraft more smooth. Mipmaps smooth out far away textures, so you don't get those ugly black grains when admiring the landscape. This is especially effective with HD textures, which Optifine supports out of the box, so no need for the MC Patcher. It also adds a lot of other options for the level of detail you want, instead of it all being either fancy or fine. The fog looks a lot better with this mod, and is more configurable. There are also other options like VSync, Smooth FPS and others that potentially help performance.
Get it here.
Connected Textures Mod
This mod has a really simple premise: It connects textures of blocks that are adjacent and same. This makes glass surfaces look a ton better. It also connects bookcases, sandstone and chests. It supports the default Minecraft texture pack, but if you want to use a different TP, you will need to make sure it's supported by the creator. Most packs do support it since it's popular, so you shouldn't have problems finding one that's compatible. All of a sudden the libraries and windows of Minecraftia look a lot better!
Get it here.
Water Shader Alpha
This is a mod for those of you with really good rigs, as it cuts your framerate in half, and is not compatible with Optifine! It does however make the water in Minecraft look stunning. The water now reflects things around it, and looks a lot more realistic. This mod takes pictures of terrain in Minecraft to a whole new level. Before it, people rendered various screenshots in expensive animation programs to make the water look this way and then uploaded them as screenshots. Words cannot describe its beauty, but maybe these screenshoots can:
Get it here.
And there you have it - awesome visually stunning mods. Which ones are you going to download, if any? Sound off in the comments section.