I've completed the Angler's Ace aspiration a few times. It can be tedious, but I just set them up fishing with a stack of bait and then get a snack, read a book, start some laundry, or other household chores for a bit. I have a few tips for finding some of the rarer fish.
1. Pirahnas love Perch and the Red-tailed black shark love Pirahnas. I've caught both at the way back fishing hole in Oasis Springs park. As someone mentioned, you can find a wide variety of fish in that spot. If you don't have Level 10 Handiness to access the Forgotten Grotto, Batfish, Angler fish and the Wolf Eel can all be caught at this spot too with the right bait.
Plus, that's a great spot for cowberries and violins if your Sim is poor and needs some quick simoleans. :) Here's a tip about the cowberries, don't sell them from your inventory if you don't want to plant it. They'll only be worth 20 simoleans. Take them home, have your Sim plant them and then go into build mode and sell them. They'll be worth 475 simoleans each!
In my experience, the Angler fish like Salmon and Koi best, but sometimes Bass or Catfish work too. There seems to be no rhyme nor reason to what kind of bait Batfish like best. I've caught them with no bait in Forgotten Grotto. The Wolf Eel will only bite when using frogs. Don't bother with the more expensive frogs, save those for breeding. They will bite on any kind of frog. Sometimes it takes a LONG time to get them though.
2. Another area to catch rares is at a fishing spot behind the Museum in Willow Creek. It's the one right next to a bank wall with a frog log next to it and a couple picnic tables above it. Very pretty area and if your Sims get hungry, townies reliably grill at that picnic area so you can snag a snack too.
3. The fishing spot on the pier in Magnolia Promenade is also a great spot for fishing up rares using the above bait. Especially the red-tailed black shark. Plus, I catch dragonfruit and voodoo dolls, which go for 900 simoleans a pop, there all the time. Another great fishing spot for poor Sims.
4. There's three fishing spots in the back of Willow Creek park. The middle one is where you'll catch rares, the other two are just common/uncommon fish. You can fish up dragonfruit at this spot too.
5. For catching common/uncommon fish, I have the best luck using more expensive plants such as blackberries, lilies and snapdragons. But, sometimes just basil works really well too. You'll have to experiement with those to see which plants your particular fish prefer. It seems to be different for every area. Sometimes using plants found in the area you're fishing works the best.
6. My favorite fishing spot of all time is the pond and falls in Sylvan Glade. I've found more varieties of fish there than anywhere else. If your Sim can stay there for long periods and you have Outdoor Retreat, use the enablefreebuild cheat to put down a cot or tent, cooler, (or bring those from home), outdoor shower and either a Get Together bush or toilet. They can stay as long as you like that way.
Also, if your Sim is a gardener and can 'talk to plants', plant something on that lot and when it grows, they can talk to it to fill their social needs. It helps a lot when your Sim's social is low and they can't call anyone because it's late and they're sleeping. As an added bonus, they'll level up in gardening! :)
7. Lastly, have your Sim bring an element, fossil or Yoga mat in their inventory as well to keep your Sim in the focused mood. They can 'place in world' these items anywhere you're fishing and then just put them back in their inventory when finished. Don't forget to pick it back up though, I've done that few times. lol You can always go back to get it, which is a pain if you don't plan to fish in that spot again. But if you will be fishing there frequently, you can just leave those items there, they won't disappear.
Hope this helps and Good Luck! <3
