Being in the Festive Christmas mood, I've had the Fireplace theme since Thanksgiving that was free a while back.

Journey Dynamic Theme I got from PSN+

I use the Sound Shapes theme because its looks awesome.

I use the Prince of Persia Trilogy Dynamic Theme. Has the Sands of Time loading icon spinning in an area reminiscent of the time portals in Warrior Within. Very cool, not too active or busy to be distracting. And all the icons are easily visible. I never use any theme that makes the XMB icons at all difficult to see.

The Ico one that came with the HD collection.

I use the Skyrim Dynamic Theme, even though I only play Elder Scrolls games on PC

Currently using the Need For Speed: Most Wanted Pre-Order Theme with this as the background image 

The default.

When it comes to themes and avatar icons available for download, XBL puts PSN to shame. Unfathomable depths of shame.

I have both systems and I wish the aforementioned disparity didn't exist.

The Giant Bomb theme, duh!

I want that Corn theme, but I can't find it. So far I've used the default theme and alternate colors every once in a while.

I am currently using the flower one that came with the Journey Collection.

oddly enough there arent a lot of dynamic themes on the ps store where i live. and most of the ones that are there are shitty as hell. but im using the heavy rain one http://www.youtube.com/watch?v=uNBNiIMsFd8

i like it its dark enough and nothing crazy happens.

I have a sweet ZX Spectrum theme I got off some website. Do I care about the Spectrum? Nope. But it does look really cool as my XMB theme.

The theme I unlocked via FFXIII-2

I have a London theme. Can't remember the exact name

I'm using one that has mac themed icons. Its my favorite.

I'm using a Digger HD one.
 
My girlfriend (and owner of the console) uses one from Final Fantasy XIII-2.

I have been rocking the same free one I got for being a PSPlus member. I still kind of like it even if it isn't that special.

Double Dragon Neon

Underwater Disco. Didn't even know I had it until I went browsing through my themes. It is glorious.

Using the Journey dynamic theme that I think comes free with either the game or just in the PSN store.

This custom one. It changes to a green one too, sometimes.EDIT: Here's the same exact one.

http://www.youtube.com/watch?feature=player_embedded&v=FXq__rArW18#!

Purple default, represent.

Wartime pin-up girls. Wife is into pin-up things.

Still in season with the Yule log screen.

I like the nature themes

umm... modern wardare 2 theme

i've more than 30 themes on my ps3 :D

@tackchevy said:

Indeed. :D I've recently gone back to that one.

I've used the Heavy Rain raindrop one, and the Journey theme for a long time. Also, a seasonal theme during Christmas time, always.

I don't use any of the dynamic ones...most seem trashy. I just use the standard icons alonmg with a wallpaper that I change from time to time. I hope Sony totally reworks how and who makes themes for PS4. Most of the PS3 themes seem to be made by idiost who couldn't draw worth a damn.

i use this one called fantasy mountain. its like little cardboard/construction paper animated mountains/rivers/clouds its pretty cool.

Default at this moment. I'm still looking for a nice theme, kind of done with the ones I have.

I switch between Assassin's Creed III, and Far Cry 3. They're the free ones I got with the game, so Meh!

I switch between Its Always Sunny In Philadelphia and Arkham Asylum.. But like the guy said earlier, the noises on that can be quite annoying.

Darkstalker Kaathe theme. First thing I downloaded from PSN.

I really couldn't find a theme I liked, wish I could have a Persona 4 theme. I was able to find a weird Japanese girl theme with a sword and some floating petals. I've never screwed around with the Dash on my Ps3 before can you put your own images in the background?

@eightbitshik: Yes, you can have your choice of image as a background. The picture has to be on the ps3's hard drive, go to where it is and there should be an option to set as background, by pressing triangle, I think.

Also, there's this thread.

The Neon Graffiti one. Before that I had the Dragon dynamic theme, which was pretty good.

FF 13-2's, cause it's about the only one I have beyond the standard ones. And I don't care enough to search others out.

I use the fireplace theme they released a couple Christmases ago. It makes sure I stay classy.

Currently using the dynamic fish tank theme that was free from when PSN was down.

I've had the Shadow of the Colossus dynamic theme for what seems like an eternity. It's so peaceful and soothing

I am using the Double Dragon Neon one that I got for free.

Wow, alot of Double Dragon Neon's. Weird. I usually switch the icon set to match the wallpaper I use in the background. Currently I'm using a Bioshock Infinite wallpaper, but if I do dynamic I use a nature one or any of there 1239123012 other themes I seemed to have collected over the years.

The free ones from "the studio" on PS+ are nice. Right now it's an abstract art kind of thing with spinning shape bits or something like that.

I've been using the Neo Geo Station theme. I like how it shows a different background depending on the time of day.

Gallery

Pretty neat that they included SNK of Japan's old mascot, G-Mantle in a few of the wallpapers.

I've been using the Shadow of the Colossus dynamic theme that came with my copy ever since.. well, release.

This! Exactly the same thing. haha

the last of us static theme in preparation for the last of us

Until this moment I was unaware PS3s had themes. So I use the default, apparently.