Yeah, the Residence is also Midtown and you'd need a car. All three do have airport shuttles (and those shuttles may also run downtown--check with the hotel front desks, though) but are in areas rather devoid of interesting things.

The Fairfield is a long walk from a few chain restaurants (Golden Corral, TGI Friday's, Taco Del Mar, Starbucks, Applebees, Stuart Anderson's Cattle Company, and Lonestar) but literally nothing else except the restaurant in the Crowne Plaza next door (Juno).

The Springhill is next to a movie theater and a moderate walk to the Loussac library (not bad as far as midsize-city libraries go) and a reasonably good approximation of a taqueria, Burrito King. The other way, there's a Wal-Mart and then some options along the Benson corridor, but that's getting a bit far to comfortably walk.

The Residence Inn is nestled in a forest and not really walkable to anything interesting except (for lunch) the surprisingly good cafe in the BP building. There's a Subway and Qdoba at the corner of the Seward Highway and Benson, but if you really want a treat, the Anchorage institution known as Moose's Tooth is almost directly across the Seward Highway. Unfortunately, you have to walk all the way down to 36th to cross the Seward Highway (or up to Benson), so it's a bit of a trek, but totally worth it. A decent import of an authentic New York-style Italian eatery (Nino's) is on the way to Moose's Tooth, and just past that is the very good clone of a real Chicago hot dog and Italian beef eatery called Johnny Chicago's (the only difference between it and, say, Portillo's is the price--he has to air-freight his Vienna Beef).

The Courtyard is much closer to the airport in the part of town known as Spenard. Parts of Spenard can get a touch seedy at night (although I wouldn't feel uncomfortable walking in the part of Spenard that the hotels are in, and the hotels themselves are 100% safe, so that's not a concern), but there are some decent things to see and do in that area. Lake Hood is just behind the Millennium Hotel across the street, and you can watch authentic Alaskan seaplanes landing and taking off all day. Food-wise, there's a Taco King (sister to the aforementioned Burrito King) and then a very good Indian-influenced pizza kitchen run by a Pakistani couple (who brought Pakistani spices with them) as well as a Subway, Wendy's, and McDonald's and a decent (but not memorable) restaurant in the Millennium across the street.

As good as some of the above options are, there's literally nothing else, so that was to illustrate that you really do need a car if you want any options. Be sure to compare prices for picking up a car on/before May 31 and picking up on/after June 1--the price differential will shock you. I'd recommend the former.

If you really do want to be in a happening area, the downtown Marriott would be your only option. There's plenty to see, do, eat, and otherwise keep you occupied downtown.

Enjoy your trip!