Classic L o l i t a
Kagome is a nice kid, I don't like the way she is sometimes, always jealous, bragging about the guys to her friends in the present, her school uniform, but she's a good person.
Kikyou is just plain cool and kick butt. She's nice at heart but she's not a pushover
The only reason why Kagome "brags" about Kouga and Inuyasha is because her friends kee bugging her about them. If you rewatched the episodes where Kagome tells her friends about them, Kagome clearly thinks to herself: "Oh s**t, I don't want to bring up Inuyasha to my friends! How do I get around this?"
In the end, she chooses to talk about them as any teenage girl would about two guys fawning over her. Yes, Kagome is very jealous of Kikyou, but who wouldn't be? Most women love getting attention from the man they love, it's natural for her to feel that way. And Kagome being Kagome, she isn't afraid to let it show, thus her jealousy is magnified times ten.
As for Kikyou, she's awesome and very thoughtful, and it was wonderful to see that Kagome and Kikyou finally overcame their hatred for each other on Kikyou's dying day, because they came to understand each other. I really loved that panel where Kikyou gave everyone her very first real smile. Anti-Kikyou fans are just full of immature jealousy for her because they all know that she'll always remain number one in Inuyasha's heart, dead or alive.