I hate both gardening and fishing (in both real life and the game!) so the science career is a no-no for me.
The only careers I have completed are Emperor of Evil and the Firefighter track. I really liked the FF career - my dad used to be one so it's always held an allure of intrigue for me.

I like my stay-at-home hackers. If not that (or if I want to get a sim out of my hair for a few hours a day), I usually go for either Journalism or Military, because of reasons.

I'm not sure what's 'best' though. I usually just go with what I feel like at that moment.

I really like the artist career, acting, and science. Those are my "big three". I was also a fan of the Ghosthunting career but it's a little bit repetitive.

I guess I'm weird, I really like the science career track, if I get bored of them fishing I just go work on someone else in the family (because there's always a family in my game). I really like the Culinary career and I don't mind Medical except for the combination of problems that came up with the late night and ambitions, if you have a star as your doctor while working in one of the extra curricular activities like free clinic and vaccinations you'll get queue stomped from helping people by fans that want to take your picture and get your autograph, I never have my sims getting this much attention anywhere else! I've been looking for a mod to block this behavior, haven't found it yet

I haven't tried the stylist, daycare, tattoo artist or the home decorator careers yet, not really my thing. The fire fighter career was great at first then something glitchy happened and it didn't work for a while so I haven't tried it again. I love all of the self employed jobs, you can set your own hours and be there for the babies so you never need to worry about a baby sitter.

The only ones I don't like and really don't play unless I'm in the middle of a legacy and it's needed is the Law Enforcement career and because of all the interrogations you have to do and the political career due to .... um.... I just don't like it *lol* Maybe it's the whole corruption in politics thing irl melting into my game that turns me off of it. All a sim politician is, is a schmoozing, moocher that's always looking for a hand out and a leg up.... bleh.

My favorites:

Culinary - I'm a cooking aficionado myself and I always like to have at least 1 natural cook in the family so we get a variety of meals. When starting a new family, the kitchen is often the one place I splurge on with a good fridge (so leftovers don't spoil) and a good stove.

Writing - Okay, not a career exactly, but I am a writer by trade and I love having Sims sit at the park with their toddlers and crank out books while the kiddo plays. And they get MONEY!

Science - Many of my Sims like to have gardens and play outside, so Science is a fairly natural career choice. I like the shorter hours, some days off to play with the family, and I find it easy to skill build for this career.

My Least Favorite:

Professional Sports - I tried this once. Getting to level 3 just about killed me. Just not for me.

Political - I am not a social butterfly type person, so the Charisma skill building put me way out of my comfort zone. I did get Julia Zelman to be Leader of the Free World, though!

Criminal - For obvious reasons. The Family Oriented human is simply not going the Evil Sim route. I did try it once, though, and the dude got sent to jail a lot.

I use the office career a lot, it's a nice placeholder for sims that I don't have any plans for.

The ones I like the best is the Science career, daycare and culinary. For self employed sims I tend to choose writer, painter or gardener.
Don't use the AMB ones too much but I do enjoy them.

I like the politician career. The working hours are very manageable, you can throw funding campaign parties at any time, you get your own personal limousine...