For all practical purposes, Guiness is pretty blah in my taste.
The Boulevard Smokestack series is pretty amazing. Their Saison is really a favorite of mine.
I am a homebrewer so I have at any point, 60 gallons of beer in the house. I have almost 40 gallons(8 batches) that needs to be bottled. Motivation is running low.
If you like stouts, you should venture out a bit. Guiness is expensive for what you really get. Try some of the sixers that are a buck more per pack, venture out into things you've not heard of or seen.
Brewers I love: Deschutes, Stone, etc. My recommendation to find new beers is to try LOTS.
Edit: My other recommendation is to keep it simple. I brew some pretty radical brews. Super high IBU(hops). Funny additions like chocolate, lactose, chilli, coffee, caffeine. But when looking for "new" beer try things that are "basic" in flavor, but quality. Goose Island also has some excellent beers that are easy to come by(some that are very hard to come by too).