Thirteen Next (for me) Books In Series:
1. Blood Games, The Chicagoland Vampire series, by Chloe Neill
2. River Marked, the Mercy Thomson series, by Patricia Briggs
3. The Undead Pool, The Hollows series, by Kim Harrison
4. Naamah's Blessing, the Kushiel's Legacy series, by Jacqueline Carey
5. Tricked, the Iron Druid series, by Kevin Hearne
6. Magic Breaks, the Kate Daniels series, by Ilona Andrews
7. The Kraken King, (all parts*), the Iron Seas series, by Meljean Brook
8. Out of the Darkness, the Offspring series, by Jaime Rush
9. Crossroads, Southern Arcana series, by Moira Rogers
10. The Mage in Black, the Sabine Kane series, by Jaye Wells
11. Darkness Rising, the Dark Angels series, by Keri Arthur
12. Dark Skye, the Immortals After Dark series, by Kresley Cole (I'll be honest, I'm waiting for this one to come down to mass market pricing)
13. Sixth Grave on the Edge, the Charley Davidson series, by Darynda Jones
And a bonus, Night's Honor, the Elder Races series, by Thea Harrison which I'm technically, not behind on as it's not out quite yet...
*this was published in 7 or 8 parts as a serial, and is showing available on November 4 as a compiled novel. w00t!
Find more Thirteeners at Thursday-13. Participants are welcome and encouraged to leave links in comments.