"And as you go forth today remember always your duty is clear: To build and maintain those robots."
https://en.wikipedia.org/wiki/The_Secret_War_of_Lisa_Simpson
Seriously though, there are a lot of jobs that will never be replaced by machines. The blue collar fields are most affected, though.
Which ones though?
Prostitutes, maybe? Some of those jobs can be replaced, but I'm sure there'll always be a market for the human touch.
Up until they make "suitable" androids for the job.
Once we've got
computer systems that can truly learn things on their own, and recognize patterns and use that knowledge, it will be possible to automate a lot of formerly untouchable white-collar jobs.
Even before they reach human-level intelligence, they'll still be close enough to automate away some jobs.
(Then the next big economic impact will come when these learning systems are turned loose on the stock market, and start to analyze and find complex correlations that no human mind could comprehend.

)
We're pretty much getting there. Lots of labor has already been automated, whether it's skilled or unskilled. So the jobs are going to be in developing new machines, programming, maintenance, etc...
Yes, this.
Watch "How It's Made," at least the episodes that show factories. (There are still various episodes showing one or two people hand-crafting items. I tend to skip those myself.

)
These places can churn out enormous quantities of product every day. The data analysis necessary to make some of these processes very efficient would also have required, instead of a high-end server system, a few thousand people analyzing the information to get the same result. The world's total count of computers alone represent an incredible leap in productivity for the planet.
I work in a manufacturing environment, and we don't just use automation as a way of keeping labor costs down. It's also used to make a more consistent product with more repeatable quality, and to increase capacity of the production facility. A normal electronic pick'n'place machine can put down around 10,000 components per hour on the large circuitboards made there. It places them reliably, accurately, and in the proper polarity. It takes quite a few people to reach 2-3 components per second of throughput, and then additional people are required for testing and inspection to find parts that were placed incorrectly or backwards.
In terms of speed, some jobs simply
can't be sped up. You can't really have 4 people working to place components on a single 4x5" circuitboard at the same time, whereas the machine will be able to finish that same board very quickly on its own. This gives quick turnaround time on very small batch orders, leading to a competitive advantage.