This (Mr or Mrs Toccata's) is a pretty exhaustive and interesting account. I feel exactly like this chat-friend with respect to Mahler and Bruckner but not concerning Bartók: I like very much his 4th and 5th SQ, Sonata for 2 pianos and percussion, Music for string, perc. and celesta, Bluebeard's castle (even though I strongly dislike operas), Cantata Profana and, though to a lesser extent, his Concerto. As to Shostakovitch, I never listened to a whole work of his, I only "overheard" sometimes a few broadcasted minutes of something. Surprisingly it was always less bad than I expected with my notoriously biased taste; the same thing happened with a few works of Tchaïkovski, Dvořák, Mendelssohn, even with a piano trio of Chopin, whose works are possibly somewhat more than merely catchy with their mawkish sentimentality and their flashy brilliance but not for me: I strongly dislike them. But unlike Mr or Mrs Toccata, I am a bad guy: I don't even try and struggle to appreciate composers I am biased against.
On the other hand, I am sympathetic to some kind of composers and so I am not unable to listen even to those of their works that smell of the lamp, for instance to Schumann's dull symphonies and chamber music. César Franck is also for me such an honest and mildly boring composer, without anything great to boot, like that handful of sparklingly inventive piano compositions that make Schumann a very great composer. Janáček: same kind as Franck but better.
Frankly unbearable are for me: Honegger (on the top of the list), Hindemith, Richard Strauss. Once a fanatic of Honegger managed to expel me from my own living room with an execrable rumble which was supposed to celebrate a locomotive; some other music-friends followed me into the kitchen. Two other works of H., which pursued us through the wall, were not less of a torture even without any reference to mechanical devices. Fauré, Sibelius: sheer boredom. Not so Mozart: he makes me only nervous except for two violin sonatas, in e and G (K 379), which I find excellent, intimate and both carefully and inventively elaborated, and the Flute Quartet in C, a little ambitious cute entertainment piece. Otherwise he usually starts up bumptiously (far less, of course, than Berlioz, Liszt or Bruckner) with good melodies but after he rarely lives up to his promises. I admit being more antipathetic to him than he really deserves. (By the way, Berlioz' Fantastic symphony is bumptious but even so I like it with Stokowski, as well as his Harold in Italy with Josef Suk on the viola and Dietrich Fischer Dieskau - yes, no mistake! - conducting.) I don't like Vivaldi either: I am certainly wrong but I can't help finding his music only pleasing but superficial.