Cookie, I also am enjoying the bachellor-pad lifestyle, and cooking is a big part of it. I like cooking in general, but cooking for myself is the best-- mostly because there is zero bitching, and I know exactly what stuff I like.
Last night I made Kim Chee Nabe (hot pot). In the cold winter, Nabe in general is really popular here in Japan, but I like Kim Chee and its really easy to do. It basically consists of:
1) boil hot water.
2) throw in Kim Chee, veggies, mung bean noodles, tofu, and won tons
3)add beef
Then eat it with rice. Good stuff! Outside Kim Chee, I also do Ton Jiru occasionally (miso and pork base), as well as just Shabu-shabu (no sauce in hot pot) with ponzu dipping sauce.
Of course, adding udon or soba to the leftover soup or adding rice to make okayu can be very nice (especially the kim chee okayu!).
Also, Ramen (especially won ton men), Udon, Soba, Spaghetti . . . basically noodles are really easy to make so I end up doing them alot.
. . . Spam Musubi . . .
In terms of Spaghetti, I like to try a lot of different sauce types, but the most common (in order)
1) Tomato (w/ Enoki mushrooms, Spinache & Broccoli)
2) Lemon Pesto (sometimes with cream or tomato added)
3) Cream (broccoli, tomato slices)
4) Meat (with Mushrooms, usually maitake)
5) Lemon Juice / Olive Oil / Parmesan Cheese (super lazy!)
6) Mushroom spaghetti (Garlic/oil sauce with maitake, enoki and other mushrooms)
7) Ume (Pickled Plum), Shoyu (soy sauce) and canned tuna (this one is odd, but surprisingly good).
Some other really easy things I will make / eat when lazy: Mizu-Gyouza, Yaki-Gyouza, Chao Han (fried rice), Cold Soumen (though too cold for this now), Ponzu shirotaki, Miso Katsu (buying the pork katsu at the supermarket), Cup Pho (lol, instant-alicious), unagi-don (once more, buying the unagi pre-maid), Yakisoba.
When I get lonesome for the US, I just make a huge stack of Peanut Butter Jelly sandwhiches. lol