So the only tournament I'm currently signed up to for 2018 is GW Heat 2 which is mid April.  I've got a few armies I could choose between to take:

Sylvaneth - Dreadwood, painted it at the end of last year but still not played a game with it.

Blades of Khorne - I've got a reasonably chunky khorne army, I enjoy playing them but it's mostly an infantry horde so not the most interesting visual spectacle.

Maggotkin - Triple GUO would be the list I'd like to play but currently I use a non-GW model for one of my GUO so would need to buy and paint another just for this event.

Skaven - I've got a pretty hefty Skaven army, so could put something together.  Might encourage me to paint up a handful of models I've had sat for a few months that I should really get round to doing.

Moonclan - An army I really enjoy playing but the basic grots aren't painted terribly well, I would probably want to put some effort into making them look better.

Tomb Kings - They'll be quite a unique army, can't imagine too many people will run them these days.  Not terribly well painted however.

I don't want to take a top competitive list, playing that way isn't of interest to me right now.  But I also don't want to get crushed into the dirt every single game.

What I'm trying to decide around is more relating to whether I try to take an army and try to get myself a painting nomination.  Most of my armies are nicely painted but I don't think they quite hit those heady heights so I'd definitely have to put a little more effort into trying to push their quality a little further.