BOO! PopCrush would like to wish you a happy Halloween with these pictures of the best celebrity Halloween costumes of 2011. Many non-musical celebrities took a stab at dressing up as their favorite pop stars this Halloween, including the anchors from 'Good Morning America.' Three of the four 'GMA' anchors wore replicas of outfits by Nicki Minaj, Beyonce and Lady Gaga, while one the hosts wore a Jo Calderone costume.

In addition to the 'Good Morning America' hosts, comedic actress Leslie Mann (you probably recognize her from her role as Katherine Heigl's uptight sister in 'Knocked Up') dressed up as foul-mouthed rapper Kreayshawn, and Nicole Richie did her best J. Lo impression circa Lopez's 'Jenny From the Block' and 'Love Don't Cost a Thing' era (remember when she made the velour jumpsuit a must-have fashion item back in the day?). Actress Holly Robinson Peete also had heads turning with her spot-on Lil Wayne costume.

The 'Glee' cast really represented this Halloween, with Chris Colfer donning an amazing and very sparkly DIY sea monkey costume, Amber Riley wearing a fabulous Nicki Minaj costume and wig, and Jenna Ushkowitz and her buddy dressing up as the Green Monkeys from Nickelodeon's old-school game show 'Legends of the Hidden Temple.' Lil Wayne also repped for the musical stars, sporting a creepy green skeleton mask, and Big Boi wowed us with his intricate Day of the Dead inspired makeup. Jessie J and Selena Gomez decided to dress up before their performances over the weekend, with Ms. J donning a skeleton body suit and Ms. Gomez wearing a witchy getup.

Scroll through all of these celebrity Halloween costumes from 2011, and click on the 'Captions' icon if you are curious to see who is who within the gallery. Who do you think had the best costume? Leave us a comment below!