Behold, Here's Poison -- Georgette Heyer

Um, yeah.  This is a must read.  I mean it.  If a murder mystery set in a 1930s Upstairs, Downstairs-type wealthy household sounds AT ALL interesting to you, you must read it. 

The Murderee: 

Gregory Matthews -- Uncle, brother and brother-in-law, head of the family, and well, total prick.  Anyone who's willing to speak ill of the dead will tell you he had it coming.

The Major Suspects:

Harriet:  Sister of the deceased.  Spends most of her time being cheap, fighting with her sister-in-law and sniping at her niece. 

Gertrude:  Other sister of the deceased.  Doesn't (thankfully) live at Holly Lodge, but sails in periodically, rips everyone to shreds with her blunt observations and sails out again.  One of the few members of the family to actually get along with Gregory.

Zoe:  Sister-in-law.  She and her two children (see below) have lived at Holly Lodge since the death of her husband.  Known for having Christian values when it's convenient, her theatrics and false empathy.  Basically, she's a big faker who pretends to be all New Agey and Caring, but she's just Out for Herself.  And occasionally for her children, but only if it doesn't Put Her Out.

Guy:  Zoe's son and Stella's brother.  Uncle Gregory threatened to send him to South America.  Guy wasn't a fan of the plan.

Stella:  Zoe's daughter and Guy's sister.  Wants to marry the local doctor, but Uncle Gregory was Against the Match.

Randall:  Cousin to Zoe and Stella, nephew of Gregory.  The other family member who didn't fight with Gregory.  He inherited almost everything.  Known for his big-spending, gambling habit, fancy clothes and cutting remarks:

"Experience, my dear aunt, leads me to reply with confidence that whatever it is you have to say is not in the least likely to interest me."

RAD.  I LOVED IT.

The mystery itself is kind of eh -- G. Heyer doesn't give the reader enough clues to figure it out, and it's kind of silly -- but whatever.  It isn't about the mystery, really.  It's all about Randall.