The first is from Seasons 1 and 2, the last is from 3.

This is the second one from season 3 (I hated season 3 btw--Emma was gone. A true H2O fan wouldn't ever except Bella or any of the new characters.

i know! season 1 and 2 look soooo real! season 3 is like real but it looks faker than the others

^ oh yea and i really don't like bella either. i want emma back! and i also dont like will. believe me. i am a very true h2o fan(: i didnt like season 3 either. mostly because of sophie. she ruined the whole season. she's mean to the mermaids and her brother and she makes zane cheat on rikki(btw, i cried when he did. hate sophie.) but the only thing about rikki and cleo- their personalitys change SO MUCH! Rikki was the rebel and not girly at all. Now she's more like Emma. Cleo was so shy and afraid of Zane and she wasn't as smart. But now all of a sudden, Cleo is more outgoing and smart... And she stood up to Zane in the episode "The Dark Side" ! What the heck happened?! It was only 1 summer!

^Oh I hated the personality changes with Rikki and Cleo too (I didn't really mind Cleo's changes but some of them just seemed odd.) But when Emma left they made Rikki act more like her, which made no sense.

As a character I don't mind Bella actually I prefer Emma of course but I'm more bothered by the shift that Bella brought to the group, the dynamic between Rikki, Bella and Cleo just seemed so odd, they became way to close with Bella to quickly. But I really don't like Will, he just irks me.

I hated all of the season 3! Rikki and Cleo definitely changed, Will was just there, Sophie was supposed to be some kind of enemy I guess, and I hated that the Juicenet was gone! That was like, their place (other than Mako, of course)! Why did everything change? Rikki was all of a sudden responsible! I liked it when all of their personalities clashed- that made a great story. And I also loathed that the ending wasn't too great for me! Rikki and Zane were going through financial problems and that was just depressing. It also ruined their relationship. Rikki's shut down, Zane and Rikki broke up, Lewis left, Emma left, Bella sucked and the girls did seem to accept Bella much quicker than I would have expected, and the lockets were no longer important I guess. Those were much better than some stupid rock. They symbolized the girls' awesome relationship. Overall, Emma should have been back, the personalities should have remained, and the characters should not have generally sucked. The End.
Sorry for the length, I just had to say a few things...

I know! Rikki is supposed to be the carefree one! NOT RESPONSIBLE!! THATS WHY I LOVE HER! SHE DOES EVERYTHING WITHOUT A CARE IN THE WORLD! AND RIKKI AND ZANE SHOULD NOT HAVE BROKEN UP! THAT WAS MY 3RD FAVORITE PART OF H2O!! (OTHER THAN MERMAIDS AND RIKKI) The cafe was definately ruining their relationship. You can tell. But in "Valentine's Day" (just about the only good episode in season 3) they tried to rebuild their relationship but that all changed the next episode! And I know! Everything bad happened when Lewis and Emma left. And i know the ending sucked! Emma was meant to come back! not Lewis!! Rikki and Cleo practically just FORGOT about Emma and the lockets!! As for SOPHIE AND WILL!, They need to go away and NEVER EVER COME BACK!! They both pretty much ruined Rikki and Zane. Will because Zane is VERY easily jealous and SOPHIE! Oh gosh. WORDS CANT EVEN DESCRIBE HOW MUCH I HATE HER! But if i had to choose some, They'd be, JERK,F-ING MORON, BOYFRIEND STEALING, B- TO YOUR OWN BROTHER, HIS GIRLFRIEND AND HIS BESTFRIENDS JUST BECAUSE SHES JEALOUS, COMPETITIVE, RELATIONSHIP RUINING, F-ING COW!!!! Can not STAND Sophie. Cleo all of a sudden, is the fearless one instead of Rikki. Rikki worrys about EVERYTHING, she's oveer- emotional, Suddenly mature, and isn't self-centered?? WHERE IS THE CAREFREE, NOTHING-CAN-BOTHER-ME, IMMATURE, SELF-CENTERED, TOMBOY RIKKI I KNOW AND LOVE??!! And something else i noticed? NOBODY except for Cleo to Lewis says i love you? Not even Rikki and Zane and they've been together the longest! (47 episodes!!) Whats up with that?? Ok This is really long so i'm gonna end here but there is MUCH more things wrong with season 3.

OK WOW. I feel the same exact thing, even though the things I miss most are the Cafe (I just love that place), the personalities, and EMMA. If nothing changed in season three, it would be PUUUURRRR-FECT. ABSOLUTELY PERFECT. BUT, I CAN ONLY HOPE. By the way, I'm going to have to give you more props for that awesome reply. Thanks!

Things I miss most are:
1.) ZIKKI!!</3 (of course thats expected)
2.) The personalities of Rikki and Cleo :((
3.) Emma and Lewis! D:
AND WTH IS WITH WILL'S CRUSH ON RIKKI IN "MERMAID MAGIC"????!!!!!! SHE. HAS. A. BOYFRIEND!!!!!! GOSH WILL! BELLA IS THE ONE FOR YOU! YOU BOTH DON'T BELONG ON H2O! D:< it makes me mad at how many people think Will should date Rikki. NO WAY! ANY TRUE FAN OF H2O KNOWS IT GOES:
CLEO AND LEWIS
RIKKI AND ZANE
EMMA AND ASH OR BYRON
BELLA AND WILL!!
I really hopee Sophie and Bella and Will aren''t there if there is a season 4.... REALLY hope.

the season 3 tails looked really bad. Especially when Rikki first got captured by the tentacle :|

if you ask me i liked the season 3 tails more they were better just the end of the tail was a little fake but if you look at the other part of the tail it is brighter shiner than the old one!
and yeah i saw that there was changes in characters personalities !
except Cleo you think that she changed in the third season? not much!
except when she was more interested in school but even that in season 1 and 2 she was a good student! but Cleo was outgoing from the middle of season 1 and from season 2 and on! like when she was always the only one who attacked Denman's and the others when she got exposed she was the first one that stood up to Charlotte in Final! and she was the only mermaid that works and got a job although Emma and Rikki didn't like that idea! she was the glue between Emma and Rikki in most of the episodes , she was the leader in most of the episode like when she always cared about her friends and the mermaid anniversary! what else in season 3 she said great leadership lines in the last episode graduation! and she gave Rikki a chance to learn more about the tentacle ! but Rikki was 100% changed she became so pressured about the new caffe and a lot of other things , Bella is ok i think she was a great mermaid! but missed Emma too! was so mad when there was no Charlotte or Lewis.! but hope they will come in season 4 if there is!

^^ I think Cleo changed but not as much as Rikki. Cleo was the shy one. Now she stood up to ZANE?! And I agree with the "Glue between Emma and Rikki" thing. Truth is, Emma and Rikki fight A LOT and Cleo is always the one that settles it. And oh yea. Rikki changed soooooooooo much. She was the rebel and the tomboy. Now she's the careful one and GIRLY?!!! I loved the old Rikki!! What happened to her??

KK this is how I see it when Bella came she got to much attention and storylines for a new person (that I would have liked so much better with emma) but whatevs I really want a season 4 just to clear everything up!