I love his entire filmography, but The Master hands down.

There will be blood I think is his best, but boogie nights is my favorite.

Right now Inherent Vice, but it changes all the time.

Personal favorite of his is Magnolia

I'd cite BOOGIE NIGHTS as his masterpiece, and it's far from great. This guy has precious little of worth to say, but his movies are presented as all-important. He doesn't know much about people and it shows in his work. He gives us paper thin caricatures but treats them and their plights as though he has a deep level of insight and understanding about them and their predicaments. Anderson is a joke and is easily the most unjustly overpraised filmmaker in recent memory.

Magnolia by far for me.
Having an opinion can save your life. Just ask Marvin.

You could make a strong argument for any one of them being his best (with the exception of Sydney), such is the variety and immense quality of his body of work.

PDL is pretty perfect th16d0e more I think about it. The variety of responses in this thread is quite telling.

Definitely agree. Punch-Drunk Love is a masterpiece and my personal favorite.

1. Punch-Drunk Love
2. Boogie Nights
3. There Will Be Blood
4. Magnolia
5. Inherent Vice
6. The Master
7. Hard Eight
   All 10/10 in my book.

There Will Be Blood
and
The Master
Rooney Fassbender and Joaquin Blanchett

Hard Eight is my favorite. There Will Be Blood, Inherent Vice, & Magnolia follow in that order.

Boogie Nights

The Master, with Magnolia as a very, very close second, and poised to get even closer with a few more viewings.

1. "There Will Be Blood"
2. "The Master"
3. "Magnolia"
4. "Boogie Nights"
5. "Inherent Vice"
6. "Punch-Drunk Love"
7. "Hard Eight"

There Will Be Blood, The Master, and Inherent Vice are all on another level of filmmaking that most modern filmmakers wish they could achieve.

I can't decide between There Will Be Blood and The Master.

Ok, so
The Master
is, in my opinion, his best film. Crafted expertly, great themes, flawless execution, superb acting; it's just a great film overall. One of the best of the 21st century, for sure.
Inherent Vice
is currently growing on me. I rewatch PTA's movies like once per year (their complexity and overall different vibe are not easy to digest), so probably next year I'll give a more concrete opinion on this movie. Right now, I think it's very interesting and enjoyable.
Magnolia
would be the finest story he has told. It's his epic, and you can see how he became a better director from that movie onward.
Never seen Punch Drunk.
Boogie Nights feels to me as a Scorsese/Tarantino movie, not a PTA one. He was getting warmed up with that movie.
And that leaves us with There Will Be Blood. I've never "gotten" it, you know? Perhaps one day I'll rewatch it, and get its brilliance; but right now I have mixed feeling towards the movie.

Well there will be blood over took goodfellas as my favorite movie of all time so I guess I would say there will be blood

I probably admire The Master the most, but it is less enjoyable than his others. The acting and writing is brilliant, and it leaves an impact. But I found it less enjoyable to watch than his others. I like Punch-Drunk Love the most just because it captures the emotion so well.

man it honestly depends on the day and mood I'm in, I could make a case for Boogie Nights, Magnolia, There Will Be Blood or The Master. But I find that The Master casts this weird hypnotic spell on me every time I watch it and I just love everything about it, it flows so nicely and the cinematography is breathtaking, plus the best acting performance of the last 25 years

I think it's There Will Be Blood. I think on a technical level all his films are stupendous, but for me, none of them match There Will Be Blood.

Inherent Vice.

Boogie Nights is my personal favorite from him but I honestly think Inherent Vice might be his greatest achie5b4vement. Perfectly captures the novel's essence of a dying time in a unique, almost masterful fashion.
If you're jivin' me my man, I say to you