Ah, the anniversary bundt pan! That's the one I have. My husband bought it for me for...our anniversary. :) My friends all made fun of me because I had been wanting it for three years and dithering over the price. I make a bundt cake for most potlucks and dinner parties now--it's been worth the money!
I use box yellow cake mix that I mix with 1.25 c sour cream, pudding mix, four eggs, 1/2 c warm water, 1/3 c oil, and 1 t vanilla. Comes out delicious every time. Can also use spice cake box mix with a lot of spices, 1c pumpkin, and the rest of the recipe the same except 1/4 c sour cream. Also works with chocolate box cake mix but in that case you use chocolate pudding mix. Frost with cream cheese frosting. Guaranteed awesome dessert and it only takes about ten minutes to throw together. I buy the box cake mix on sale for $1.25.