This is ranking by 1cc difficulty (not no-bomb runs or scoring or anything), in no particular order:
LLS is significantly easier than average Touhou games-- I'd go as far as saying it's 1 difficulty lower (LLS Hard is more like a Normal, LLS Lunatic is more like a Hard). There are a few ridiculous patterns, but you can bomb them.
MS is the closest to Windows gameplay, but notably it relies more on bullet speed than density. I'd say it's one of the harder games to 1cc if you prefer planned strategies over reflex dodging as I do, but easier than the (similarly styled) EoSD, especially in stage 2 and 3. It's also like PCB in that it doesn't vary as much by difficulty-- harder Easy than average, barely any change from Normal to Hard. (Note that on Lunatic, Yumeko is up there with the hardest stage 5 bosses, due to two specific patterns.)
SoEW's patterns aren't too hard, and it's a short game, but you have to adjust to its very limited mechanics-- no focus, no health bars, no deathbombing (if anything it seems there's a bomb delay, where you have to press the button well in advance), no autocollect even by bombing, irregular bullet hitboxes, and rapid-tapping Z (or autofire) is stronger than simply holding Z. The bosses don't even change between Hard and Lunatic; Lunatic only makes stage enemies shoot revenge bullets.
PoDD is widely considered the hardest Lunatic 1cc in the series (well beyond UFO), though a lot of that comes from only getting 4 extra lives. I'd say it's worth a try even if you don't like PoFV (I don't).
HRtP barely changes by difficulty, is also a short game, and its unlimited extends every 400,000 points make it trivialized by bomb-spamming (just make sure the orb bounces off Reimu during the bomb to extend the combo). Lunatic makes all the cards shoot bullets, but also raises their point value, so you can still combo them with bombs just as easily. The bosses after stage 5 get pretty ridiculous on any difficulty and can randomly corner you, but you can bomb through them too, by using bombs to safely slide the orb into them.
(Though HRtP might seem really hard to a Normal player, if you're not used to planning out strategies yet.)