I have to say the BMW 5 series in my favourite and I have owned more of those than any other car over the last 25 years.
These have been my family wagon, mile munchers, have owned other stuff along side them.
E39 528i, 530d, 530i saloon, 530i touring.
E61 535d, 530d.
F11 520d, 530d, LCI 520d, LCI 530d and in my current lci 520d which is a 65 plate and now 165k miles on it.
Merc E Class
S210 E320cdi, E320
S211 E320cdi x 2
S212 E350d, E350 petrol (which was amazing!)
The S212 E350 petrol was superb, was around 4mpg behind the E350d overall, was super smooth as power so linear, and not really sure why I sold it to be honest. I don't need to explain the virtues of a petrol wagon to you of all people. Haha
Funnily enough, after preferring the Mercs for comfort and build in the 211 vs e60 era, I found it the other way round when it came to the 212 vs f10 era.
The BMW just felt a bit more solid, a bit better damped and interior quality a smidge better, oh, and the infotainment system on the BMW was/is superb, so ended up going back to them.
I'm now at the point where I will probably never own a new car like this again, I would rather spend money on the fun cars and other things in life, and, I just found the new design language a bit to brash for my tastes. The new e class and 5 series, just launched seems to be better in that regard, but it will be a few years before I have to consider either of those.
I was looking at a G31 540i touring recently, before deciding to keep the current car for another 18 months till my son finishes school, 70 miles each day, and then just selling it with 200k + miles on it, but also considered an E43, but don't want black interior.
My main problem and the reason I stopped looking at Mercs was the lack of interior choices, and the silly menu system, if I wanted interior ambient lighting, a ā¬300 option everywhere else in the EU, I had to have an AMG pack which gave me Ā£3k worth of stuff I didn't want including a dark interior.
I'm sure Mercedes UK has come to its senses and offers individual options again and lots of interior colour choices as all the press shots seem to be really nice light interiors? But between about 2013 and 2018 there just wasn't the ability to chose the car how you wanted it.
I should add, I meant 2 e class and 4 5er since my last reply in this thread! haha