This question is opinion-based, but I would certainly go for Abisko. But why not make it a trip and visit all three?
Abisko and Rovaniemi are both pretty good but Abisko is in the mountains and near the coast, and has more natural scenery to offer. Rovaniemi has the santa claus village. Tromsø has the prettiest scenery but the least favourable climate for northern lights, although if you go inland a bit to Bardu conditions are essentially identical to Abisko.
If you prefer natural scenery, go to Abisko to see the lights and spend the day looking at natural scenery, either from Abisko or from the sky station. Abisko has a nice canyon, is next to a beautiful lake, and has generally a beautiful valley with Kungsleden leading south, which is good for hiking or cross-country skiing.
If you prefer santa claus village and tacky souvenir shops, go to Rovaniemi to see the lights at night and the santa claus village during the day. You can also spend some time exploring the surrounding hills/forest.