Always on hand:
US-05 - I'd call this my house yeast. Good for pale ale, IPA, red, cream ale, etc.
US-04 - Good for most english styles
couple of washed yeasts, right now I'm coming off a long hiatus so I have to rebuild this. I have a brew shop within 5 minutes of my house, so I can buy any liquid yeast I may need the day I make my starter.
For Hops I keep about 1 or 2 lbs in my freezer of my commonly used varieties.
Centennial, Chinook, Amarillo, Mt. Hood (for those more mild beers), Sterling (like this in Belgians), and Goldings (out of these right now, need to restock)
Grain:
2-row pale malt, Belgian Pils - can make almost anything with just the pale malt. I may pick up a bag of Vienna soon though as I'm thinking about making a few lagers once my pipeline is full.
A few lbs of specialty malts, not much though. Right now I have about 5 lbs of C60 because I use that in my pale ale and IPA. Other than that I usually just go to the LHBS and pick up my specialty grains before I brew. It's fun to go to the LHBS and buy the special grains for my next 4 brews and walk out for under $20 knowing I've got everything I need