Horizon 1’s soundtrack is almost a complete ten out of ten for me. It’s easier to name specific songs that I don’t like from its soundtrack because it was that good. Bom Bom is a complete dud, and I am forever grateful it was never a hit in the States. Also, while the songs are good, I can’t stand listening to the Lostprophets songs anymore given what their lead singer has done. If you don’t know about Ian Watkins and you’re having a bad day, do yourself a favor and DON’T look up his Wikipedia page.
It’s harder to comment on the later soundtracks though since none of the sequels change radio stations to play specific songs for specific events, a real underrated feature of Horizon 1 in hindsight. Also, I take full advantage of being able to play Spotify in the background once a soundtrack in a game becomes stale.
Still, I’ve heard most a lot of Horizon 2’s soundtrack. Stands out off the top of my head are probably Bridge and Tunnel by Holy Ghost, Just Because by Jane’s Addiction, and the two songs by Chromeo. Best radio by far though was NinjaTune. It had great variety without sounding disconnected and muddled. Also, bonus points since NinjaTune provided the licensed songs for Blur’s soundtrack, which is also really good. Really wish NinjaTune would come back at some point.
Horizon 3’s soundtrack is probably the soundtrack I’ve listened to the least after 5’s, but this was still a very strong soundtrack. This game has easily the best version of Horizon Block Party, and two rock stations instead of one is always a plus. Standouts include Killer by Adamski and Seal, Anxiety by Bad Religion, Freedom '15 by !!!, and Get It Right by the Offspring. I could actually probably name more.
Horizon 4’s soundtrack gets more hate than it deserves, but it’s definitely a step down from the past 3 games. Horizon’s annoying “loop the song until the race ends” mechanic really ruined most of the songs I liked from this one, to the point where I honestly can’t name a favorite despite my opening statement.
Horizon 5’s soundtrack, however, is a complete mess. I turned it off within the first two hours of gameplay, but I sampled it later on Spotify to give it a chance, and I was not impressed. It’s not without it’s good songs though. About half of XS is good. I actually liked Levitating by Dua Lipa despite not listening to modern radio anymore. Other standouts include It’s Like That by Run-DMC, Intergalactic by the Beastie Boys, Rocket Fuel by DJ Shadow and De La Soul, and Straight to the Morning by Hot Chip and Jarvis Cocker.
Still, Horizon 5’s soundtrack was so much of a dud in my opinion, I ended up creating a public playlist in the same vein of a Horizon soundtrack on Spotify, and I’ve gotten at least 11 likes so far, so there’s that at least.