Why has no-one mentioned Ribspreader? Quite a good band I think. I'm too well up on the history of the band so maybe it's not a full on Swano project, but it's good nonetheless.
I couldn't pick a favourite myself though, all class bands.
The best possible start IMO, you get one band that shows Dans brutal stuff and one showing his softer side. All the other stuff falls in between these two bands (more or less anyway, I know InfestDead is more brutal than EoS and Unicorn is softer than NG, but hey... EoS and NG are better ).
Anyway, get Purgatory Afterglow by EoS and maybe Invisible by Nightingale and you're off to a good start.
Nightingale, because of their 5 excellent albums.
But I also love Moontower, Unicorn's Emotional Wasteland ans 3 EoS albums.
Odyssey, Sörskogen and Steel are good too, but there's not enough songs.