I don't pay much attention to the DPS stats, I tend to run more off effect on impact and how fast I can push target ships of different sizes into overheating. I do have a few different weapon set ups I use on my ships.
A 250 Cannon, 250 Cannon, 250 Punch system is a pretty decent medium autocannon, plus thats seems to be right around the block count it needs to be to take out Advanced Armor with one hit.
A 250 Beam, 250 Beam, 250 Explosive makes for a nice, accurate long range direct fire weapon. It doesn't do a lot to an armor shell, but it carves nice chunks out of all the juicy systems underneath.
For smaller turrets, I tend to use the above two systems either singly or in dual mounts.
If you're really pressed for space, a 100 Cannon, 100 Cannon, 100 Overdrive turret makes a nice compact turret that will tear up hull and standard armor, but doesn't quite have the punch to get through Advanced unless the targets armor pool is depleted. I need to test a 150-150-150 version of this, and see if that will go through AA, but a 450 block system running an overdrive tertiary is starting to get power-prohibitive.
Now for ship mounted main batteries, I tend to use 4 different weapon combinations determined by the ship's role.
Beam-Beam-Ion, as big as your power system can handle/you have space. I've gone as small as 1000-1000-1000 and as large as 5K-5K-5k. If you can break the shields of a target, you can kill it. I like to devote roughly 33% of my main weapon blocks here, and I've seen players go as high as 50-75%. I am starting to think I should be making this system larger in future builds.
Beam-Beam-Explosive Anywhere from 500-500-500 to 5k-5k-5k+. This is a nice big accurate sniper beam. If you get lucky, you can even burnout weapon computers on the target. However, this system is pretty useless versus smaller fighter sized targets.
Missiles-50% Beam- Punch. I tend to build these in sets of 5 vertical silos, with each silo having 200 Missiles, 100 Beam, 200 Punch for a total system size of 2500 blocks. This is getting into the territory of main missile batteries for ships having 90K+ blocks total.
Array of Cannon-Cannon-Punch. My personal favorite, Four to Six barrels, each barrel having a 750-750-750 to 1500-1500-1500 combination of systems. This will shred most ships in short order, but this systems is also the riskiest to use, got to get close, and hard to hit with. Especially if the target is fast.
The best advice I can give is to jump into creative mode, build a giant block of Crystal Armor of roughly 30 x 30 x150, and then build a mix different weapons systems and shoot them into the above mentioned giant brick of transparent armor.
Or, shameless plug alert, If you want to try some of these out, feel free to grab my 3 most recent ships off the docks. The fighters especially have an interesting little mix of weapons that would be helpful.