Salmon eggs

Cured singles work great under a float in the cricks and in the lake from shore. Sacks also work well the same way.  Floating egg sacks work in the lake well weighted down with a sinker as well as in the cricks but in slow deep pools.  With that being said I only use them during steelhead season. Never used them for any species of fish except for trout and steelhead. Not to say that it wouldnt work but ....
 

If you're talking about single eggs for steelhead, they're hard to beat for year-round consistency in the streams (don't have any experience with 'em in the lake).  They work in low, clear conditions to high fast conditions from September through March.  I prefer the cured single eggs you get at Poor Richards.
 
Proper presentation is the key: low and clear conditions - a size 18 or 20 hook, fluorocarbon leader, with very few and very small splitshot under a float or dead drifted.  More shot in faster, higher conditions, and you can go to a 14 or 16 hook.  Drifting works best, but I have also caught plenty of steelhead in low, clear conditions in slack water just letting it suspend in the pool under a small float.  Throw it out under a float and let it sit.  Never tried throwing them out on the bottom for steelhead.  
 
For trout in inland streams, they work the same.  Except don't use eggs from the Great Lakes unless you can get them certified VHS free.  Get a jar of Mike's eggs, pour out some of the liquid, and add a little kosher salt.  This will firm them up and help them stay on the hook longer.
 
Been many years since I've used salmon eggs in an inland lake for trout, but I used to use Pautzkes Balls of Fire pretty regularly.