Better Cake!
Create biome specific mobs and plants (eventually compatible with biomes created by other mods) that can be used to make food. You spawn in a new world with a recipe book that has basic recipes (bread, cake, cooked meats, baked potatoes, etc) and every time you complete a recipe a new page in the book appears for directions to make a new type of food. Eventually you'll need EU/MJ (maybe have the same system as AE?) to power some of the food processing blocks and multiblocks. Since the recipes will get more expensive (probably end up using diamonds, nether stars, and silk-touched blocks) and the flora/fauna will require a bit of travelling to acquire, the foods will eventually give you very strong buffs for long durations (creative-mode flight, silk touch, high stacks of fortune, extra temporary hearts, better underwater movement, gills, etc.
In addition to the food and processing machines you'll have to make some early-game tools to make mid-level foods such as meat cleavers/tenderizers, cheese graters, frying pans, and hunting knives (more meat per mob killed). In the mid-game you could build refrigerators that act as a cheap alternative of AE storage for completed food and food ingredients.You could enable wannabe-GregTech-mode where raw food poisons you and all vanilla foods require more work to make (mortar and pestle wheat + water = dough. Dough + brick baking oven + coal = bread)Better Homes
Adds blocks for people who want a nicer/more practical base. Things like bigger doors, secret lamps, more music disks, and directional lights (only shine in one direction in a straight line, 90 degrees, 180 degrees or 270 degrees).
That first one sounds amazingly great and brilliant and awesome, I want.