Try distant stars or Mad Scientist they are regularly posted on the forums.

 Try the 7 Deadly Sins mod, its a compilation mod, and try Distant Stars, and Epic Mod, and try Shadow's "Modes" mods they are very different and a lot of fun!!  Also try BailKnights graphic mod, i think its been merged with ManShooters Volumetric Explosions and Damage mod, its very very good.  Also give the StarTrek, StarWars and the HomeWorld mods a try, they are very very different with "classic" ships and music and it sets the whole atmosphere.  

There is also i believe a FreeLancer mod, a BattleFleet Gothic mod in the works as well. Just peruse the modding forum pages and you will find a treasure trove!!    Ahoy Matey!!! 

-Teal

One more karma for you... It is the best reply that i have ever see...

Sm, we both know i still get all the girls

Personally I think the best mod is

The BAILKNIGHT+MANSHOOTER graphical improvement mod. Since it doesnt take anything away from the brilliant design of the main game, it just adds on the graphical whistles that vanilla sins totally lacked. If it had a built in mp3 player so we could choose our own music during the game it would probably be the ultimate/end-all mod.

Then second I'd have to go with MANSHOOTER's Dynamic Battle System. It still has some minor kinks to work out, but it makes the game feel much more immersive. Standard sins, with it's stationary ships lobbing torpedoes at each other is completely unrealistic. No naval engagement has ships that just sit there allowing enemy ships to get a perfect lock on you. There's always movement, and DBS gives that feeling to a sins game.

IMO, Distant Stars IS the best mod out right now, for Entrenchment 1.03. I don't know about 7DS, having never played it, because it doesn't currently work with 1.03. Mad Scientist wasn't bad, but I was underwhelmed with it when compared to Distant Stars.

The best mod would be something that Ironclad releases.

Why? 

Because you know it would be compatible with everything.

But, yeah, ManShooter's volumetric explosions, without Bailknight's enhancements if you don't appreciate being completely blinded by eye-candy but with if you don't mind, is a total win. You get to enjoy the vanilla Sins experience and don't have to figure out new rules of the game... but get to do so with huge splodeys.