Oh, it depends.

Personally, I just go for balanced fleets. 50 of each does nicely in the way of offense and self-protection. Then keep building in sync. Thats with 2 of each capital ship, or if you can depending on the game, 3 of each. Always though, I try to have at least 100 strike craft per fleet, rising to 150 if possible.

For each way of spamming a ship, there is a counter, so balanced fleets are only really overcome by sheer numbers and better tactics. So a balanced fleet that maxes out the ship allowance, is difficult to beat if your tactics use its strengths.

No one's even going to mention Returning Armada or getting a Level 6 egg?

I'll mention RA and the Space Egg of Doom.  Of course, RA for v1.1 won't be a decisive win any longer.  Subverters are great for the illum spammers.  If they have Gaurdians, they still work, but you need to subvert them before they repulse you.

The biggest advantage that Vasari have early game is that you get LRFs with one lab.  They are a great rush race.  They are also a good end game race.  However, be careful mid-game, because that is when they are weakest.

not to mention the fire-and-forget nanobots with an insanely fast recharge that shred most ships in 1 shot

All hail the great Space Egg!

subverters work well

and if you're the type of person who likes elite but few units vasari is the race to use

if u like to attack planets the jarasul evacuator( space egg) has the planet drain ability