That is a simple question that has a complicated answer. However, here are some general guidelines.
If you are looking at spinning tackle and plan on throwing 2 to 4 oz. lures on say a 9 Ft rod, then The Okuma VSystem or Quantum Cabo is tough to beat. Both reels are specifically made for saltwater and are incredibly smooth for repetitive casting. I would not use these reels for weight and bait. If, on the otherhand, you are Drum fishing using a 12 to 13 Ft rod and "8 N Bait" go with a reel that is designed for power and not finesse such as a Penn 650/750SSm or a Daiwa Black Gold 60 or 90 or Fin-Nor's Offshore series. These are not finesse reels. They are designed to take the shock of casting, in-flight bail trips and/or hard hookups. They are, unfortunately, not the best choice for repetitive casting.
Conventional tackle is a different animal. Back to our 9 Ft rod throwing the 2 to 4 oz. or so lure, the better Ambassadeur 6500 series reels will probably suit you best. Best configured for 15 to 20 pound line max, reels like the Sports Mag CS which has magnetic cast control built in as well as a line guide will make throwing Stingsilvers and 450 Hopkins' a delight. If you do not like the line guide, go with the CT version.
If you are going with the 12 to 13 Ft rod, then Daiwa's Saltist 20H or 30H is probably the best way to go. Good from 17 to 25 pound line, these reels are great out of the box and can be made better. Be sure to get the low profile high speed "H" versions as the standard reel is better suited for deep drop fishing. Daiwa's SLOSH series is also a good choice.
Ambassadeur has a new magnetic 7000i that requires some tweaking to make the magnatic system right but that is another good 25 pound alternative once corrected.
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