Not every act out there is successful of course.

Do any of you have any acts who you like a lot but are not mainstream or haven't had the commericial success?

Little Boots is one of my favourites, I loved her album and I think it had a few potential singles. Shame she only had the one hit with Remedy.

Seth Lakeman. Have all 5 of his albums. I know he was nominated for a Mercury Music Prize for Kitty Jay and I know he's lost his way a little but I still love his music

She & Him
The Like
The Pretty Reckless

Hurts (although i know they are pretty successful in some European countries)

Annie

Roisin Murphy

Dubstar should have been bigger, along with Saint Etienne

Mini Viva
Nadine Coyle
Yasmin
Bat For Lashes

The Veronicas
Mike Posner

I never thought I'd find another person on DS who likes She & Him

The Pretty Reckless
Surfer Blood (have they had success? I'm not sure)
Best Coast
Lykke Li
I would add Paramore, but I know that they have had some chart success so I'm going to leave them off of the list.

Trey Songz
Jazmine Sullivan
Melanie Fiona

They've all done quite well in the US,but they haven't done that great in the UK.

VV Brown was a fave in 2009 as was Little Boots that same year, still blast their debut albums a lot!

In terms of "commercially successful" -

Robyn
Kelis
&
Janelle Monae

But they are successful names for critical acclaim, named artists and also fantastic at touring just wish they were more well established and known

Goldheart Assembly
The Leisure Society
Avi Buffalo
Detroit Social Club

Britney Spears could fit in to that category at the moment.

I know most of these have had moderate success, but they deserved to be a lot bigger:

Annie
Rachel Stevens
Roisin Murphy
Mini Viva
Kelis
Robyn
Sophie Ellis-Bextor
Alesha Dixon
Gabriella Cilmi
Frank
Girlicious
Girls Can't Catch
Nadine Coyle
Little Boots
Siobhan Donaghy

And its too soon to tell on Nicola Roberts, SoundGirl and Florrie, but I think they'll end up in this category too

Alesha Dixon!

Hurts
Laura Izibor
Clare Maguire
VV Brown
Band Of Skulls
Nabiha
Grace Potter & The Nocturnals

Bevis Frond
Boards Of Canada
Ladyhawke
Debbie Duveen & The Millbanks

A few but the biggest for me is Mystery Jets. Think they're amazing.

Definitely agree with the bolded ones... Especially Mystery Jets... They write quality indie pop with some really catchy hooks and melodies but still they haven't taken off!... Two Doors Down & Serotonin are both really great pop songs.... I s'pose lack of promotion will prevent anyone from making it big these days... Plus they're an "indie" band which doesn't really seem to be the in thing at the moment.

Natalia Kills
Skylar Grey

Although I'm pretty sure they're both about to explode onto the scene very soon.

Anna Abreu
Carrie Underwood (HUGE in the US, not done a thing over here bar a number 93 album - and she's my 2nd fave singer of all time!)
Charice
Demi Lovato
Jennifer Hudson
Jessica Mauboy
Jordin Sparks
Kat DeLuna
Katharine McPhee
Lykke Li
Mini Viva
Miranda Lambert
Mylene Farmer (the French Madonna, HUGE in France but hasn't even had much material released here)
Robyn (since With Every Heartbeat she's really not done much commercially )
Sia
Simon Curtis
Sky Ferreria
Solange
Tone Damli
Vanessa Amorosi (one hit wonder from 2000/1 (?) - Absolutely Everybody! Huge in Australia since then, never seen anymore UK sucsess though )
Wynter Gordon (she still has time to go big though I guess)

Fefe Dobson

Nicole Roberts.

Is she any more unsuccessful than Nicola Roberts? surely thats not possible

I disagree. I don't know many "not so successful artists" that can pull of a million selling album as well as two hit singles.
I think that defeats the point of "Not so successful"

Mimicole, nice to know you like She & Him and Pretty reckless too