I prefer more flavorful, often sweeter stouts over stand-alones. Milk stouts and chocolate stouts are more my style. A friend of mine prefers really serious stouts and he likes "Oatmeal Breakfast" stouts. Goose Island also makes a pretty serious Bourbon County porter you might want to try.
What is it about stouts that you like? If you like the toasted flavor, just keep tasting as many as you can. You may also want to try English Browns like newcastle. If it's the thic richness you crave, try porters as well as Bocks and Scotch Ales (which are generally sweeter).
In general my advice would be to taste as much as you can and do so reflectively. Meaning, if you like something (or don't), pay attention to as many features as you can. What style is it? Do people who reviewed it on line think it represents that style? What's good (or bad) about it, the grain flavor, consistency, bitterness, spices? These are hard things to do at first, and not everyone agrees on what to call the same thing, but the more you can reflect on your drinking, the more you'll develop a taste for what you like.
Finally, don't be surprised if a sip, a bottle, and a six pack all have different tastes to you, that's normal. Some beers are great for a sip but not for a bottle (and vice versa; Philadelphia Brewing Co. makes a ton of bears I don't like at first but then grow on me with the bottle); some bottles are good every once in a while but you wouldn't want to be stuck with a case.