FanficRecs Definitely Worth Reading
The idea here is that things went FUBAR at Bill & Fleur's wedding. Even though it's just Neville, Luna, Hermione & Harry left in this story, it's not a Ron/Ginny bashing story.
And while most of the fic is serious, there are some moments of humor, like the scene below between Hermione and Alt!Snape.
''"And what did you do to your hair?" She asked in horrified fascination.
Snape's hand rose to his scalp.
"Nothing! What is wrong with you, girl? I just washed it and blow-dried it like every morning…"
"Ah, I see" she nodded and stepped back. "Alternate dimension. It must be."
Albus lips were twitching. "You deduced this from the state of Severus' hair?"
"Believe me, you would have, too," she deadpanned, then she suddenly broke into an excited grin.''
Another win? Hermione had procedures in place for accidental time-travel or dimensional travel.
FanficRecs Great Dimension Travel fic
This is a dimension travel fic that is really done well. The dimension Harry, Hermine, Neville and Luna land in is markedly different (Sirius was in Slytherin and is friends with Snape, Lily and Remus are married, Neville was the boy-who-lived etc.) and the characters we know are therefore evidently different, but have enough similarities to their counterparts to make it believable that they are just different versions of the people we know. Similarly, the Harry, Hermione, Neville and Luna are also very different from their canon counterparts as Bill and Fleur's wedding turned into a slaughter and things only went worse from then on. It's a good idea to start the story with the dimension travel and not the things that happened before, since that would probably be too dark and gory, as they went through some deeply messed up and traumatic stuff. Instead, we slowly learn tidbits from their past, wondering together with the characters from the alternate dimension what could have made these four people so messed up. And, after learning about their past, is does make sense why they, in particular Harry and Hermione, are the way they are. The dark subject matter is fortunately lightened up a bit by some dark humor.
The POV is shifting so we get insight in a number of different characters, fleshing them more or less out. In particular Lily, and her reaction to her son from an alternate dimension with a man she despises, and who is off his deep end, stands out for me. There are no sappy "I love you" moments, but Lily (and Harry) are certainly affected by each other and form some kind of relationship.
The ending is not a full on happy ending - that wouldn't make sense with these characters - but it is hopeful, indicating at some point the protagonists will find peace and hapiness.