I have been trying to figure out where to find alley catfish and angelfish in Twinbrook for a long time. I discovered the alley catfish in the little bay by the bridge and in Juan Darer's pond. I found angelfish. But when all the fresh water froze over (I just got Seasons and winter has started), I needed to find a new spot. Nothing helped. I couldn't find anything here on the Forum except a bunch of people looking. I finally found out though, and the next person who comes here hoping to finally find what the title says, fishing spots in Twinbrook, will not search in vain!
This map from Prima Guides shows the fishing spots in Twinbrook and which spawners are where. (If you can't 'click to enlarge', try right-clicking and select 'open image in new tab'.) I found out which spawners contain Alley Catfish and which contain Angelfish on the Sims Wiki (can be found
here) but for ease of purpose I will tell you that Alley Catfish spawn at Lake Uncommon 2 and Ocean Uncommon 1, and Angelfish spawn at Lake Common 2, Lake Uncommon 2, Lake Rare, Ocean Rare, and Ocean Uncommon 2. They also spawn in foreign locations, check the link for those.