@Brittany401 If I were renting a two-bedroom unit, I'd expect it to include a kitchen. A small kitchenette is sufficient for brief stays, but a spacious and well-stocked kitchen is essential if you want to attract families for longer stays.
Also, these days a lot of digital nomads are using Airbnbs as their base for remote work, so setting up an appealing home-office space would give you a big boost with that market.
One key reason I suggest those two amenities over any other is that Kitchen and Dedicated Workspace are both in the short list of search filters - you can view those by doing a listing search and clicking "More filters." The more items on the search filter list you offer, the more users' search results you'll appear in, and that has a real impact on bookings. As for things that aren't on that list, anything could be a unique selling point (e.g. sauna, pool table, rowing machine), but since they're not searchable, they're unlikely to increase your page views and bookings.
One more thing - if your basement happens to be short on sunlight, I recommend investing in some really good adjustable lighting features and decorating with light tones and splashes of bright color. It takes a little extra effort to make a basement feel light and airy, but it really pays off in elevating the mood of the space.