My pet peeves with series has to do with the fact that there are a LOT of series out there. It's a lot to juggle in my mind and keep track of, especially since it takes years to finish a series. I like series, but its easier to start one that is finished than one that's ongoing, and easier to start one by an author I know I like than a new author I'm not sure of. I think that I may actually prefer standalones. Authors that write mostly standalones – Neil Gaiman, Robin McKinley, Patricia McKillip (besides the Riddlemaster of Hed). Actually – duologies and trilogies are fine too. Open ended series.. beginning to feel tired. This is the list of series I'm reading right now:
1) Wen Spencer - need to start book 4 of 4 in the Ukiah Oregon series
2) Wen Spencer – need to start book 2 of 2? maybe in the Tinker series
3) Patricia Briggs – read 2 out of 7(!!), in the Mercy Thompson series (book 3 – Iron Kissed is out Jan 08)
4) Kim Harrison – need to start book 3 of ??? (5 so far) in the Hollows series
5) Rachel Caine – need to start book 3 of ??(6 so far) in the Weather Warden series
6) Rachel Caine – need to start book 2 of ?? (3 so far) in the Morganville Vampires series
7) Dawn Cook – need to start book 2 of 4 in the Truth series
8) Kat Richardson – need to start book 2 of ?? (2 so far) in the Greywalker series
9) Faith Hunter - need to start book 2 of ?? (3 so far) in the Apocalpse series (I don't know the name of this series really)
10) Michelle Sagara – read 2 of ?? (5 so far) in the Cast in series (book 3 will be out August 07)
11) Garth Nix – started reading his Keys of the Kingdom series (book 1). Waiting for book 7 of 7 to go through it since its fast reading. YA.
12) Anne Bishop – I read book 1 of her Ephemera series (prob a trilogy), not really interested in continuing. Maybe.
13) Mindy Klasky - Need to read book 4 of 5 in her Glasswright series.
14) Moira J. Moore – Need to read book 2 of ?? (around 4 so far) in her Hero series
15) Anne Bishop – Read her Jewels trilogy, need to read her 2 other books from this world (continuations?) - Dreams made Flesh, Tangled Webs..
16) Sharon Shinn – Read book 1 of her Twelve Houses series.. not sure if I want to read 2 and 3 out of ??.
17) Karen Chance – Read book 2 of ?? in her Shadows series.
18) S. L. Viehl – Reading book 1 of 7 so far in her Stardoc series
19) Marie Brennan – Reading book 2 of 2 in her Doppleganger duology (I think)
20) Louise Rennison – Read book 2 of ?? (7 so far) in her Georgia Nicolson series
21) Casey Daniels – Read book 2 of ?? (at least 3 so far).. in her Pepper Martin series. Probably will not continue.
22) Ilona Andrews – Read book 1 of 2 so far of her Magic series
23) Lilith Saintcrow – Read book 2 of ?? in her Dante Valentine series
24) Karin Lowachee – Read book 1 of 3 in her series, will continue eventually.
25) Katie MacAlister – Read up to book 3 of her Aisling Grey, Guardian series, not really interested in continuing.
26) Janet Evanovich - Read book 1 of … ??? 13 so far in her Stephanie Plum series. Not interested in continuing.
27) MaryJanice Davidson – Read book 1 of ?? in her Undead series
28) Holly Black – Read book 2 of 3 in her Modern Faery Tale series.
29) Kristen Britain – Read book 2 of 3 (I think) in her Green Rider series.. Not really into it.. may finish though.
30) Ellen Schreiner – Read book 1 of ?? (3 so far) of her Vampire Kisses series
31) Sophie Kinsella – Read book 2 of ?? (5 so far) of her Shopaholic series
32) Kelley Armstrong – Read book 1 of ?? (8 so far) of her Otherwold series
33) Stephenie Meyer – Read book 1 of ?? (3 so far) of her series
34) Clare B. Dunkle – Read book 1 of 3 in her Hollow Kingdom series
There are other series I'm not going to even mention here since I'm now very tired. At least 10 more. At least.
K – I figured out another pet peeve – NOT KNOWING when a series is going to end!!
specficromantic 
Yeah I'm done w/ Katie McAlister's series too. The last book was supeeerrr pointless. Nothing happened. More new characters were added for whatever reason. And there was basically no plot to the book. No thanks.
Very disappointing too because you think of the time you invested in the series and the potential the series could have had. Oh well.
I wasn't completely fed up with it, but I wasn't really happy with how the same thing started to happen – people don't tell her the rules and Aisling f's up. Over and over, and then she has to fix it, which was frustrating – if people just told her instead of expecting her to know (??WHY do they expect her to know?), then half of the book wouldn't happen. And yeah, too many things going on each book… I just have too much else to read right now so its wayyy down on my list. I don't know if I'll ever come back to it.