Seward, Alaska, gateway to Kenai Fjords NP.
Once the main seaport for interior Alaska before the shipping companies decided on a better Anchorage (literally), it retains a historic downtown, a sense of walkability, has trains to Anchorage and beyond, and has a typical coastal Alaskan setting.
Wrangell-St. Elias has multiple angles of approach due to its size, but the main one is the McCarthy road. The service towns (Glenallen, Chitina, etc) are typical roadside rambles, and McCarthy itself has a few services a bit past the end of the road (bridge washed out, got replaced by an ATV track). A few miles uphill is Kennecott, within the park, a lovely abandoned mill town.
Emphasis on abandoned, though.
Katmai NP has King Salmon, a village of several hundred that's dreary tundra sprawl, and Denali NP has a tacky strip of chain stores and resorts in McKinley Village that's best driven through quickly.
Gates of the Arctic has Coldfoot, a gas station and the visitor center on the Dalton Highway, with the park a bush plane hop to the west.
Kobuk Valley and Lake Clark have only wilderness.