First let me start with some of my bad practices... :)
I hate when too many apps run in background and hog my phone memory... I have bad habit of factory resting my phone when I am too board!
What are the apps that I cannot leave without?
1. Opera Mini ( Browse like 3G on GPRS connection! )
2. Docs (google docs)
5. KeePassDroid - Same password file on phone and on computer ( install KeePass on comp)
7. Comodo ( Block spam SMS/Calls even when number is not displayed ) ( Soon I will be posting list of these numbers/site names)
One of the good thing is I have moved all my contacts to google contacts now I'm not worried about loosing any contact and every time I store new contact I directly store on google.
Here is a quick tip, I am sure lot of people must be already aware of the same but it amazed me that my phone still has surprises for me and there are still lot of areas to explore! Search any contact and swap your finger from left to right and it will call its default number! swap finger from right to left and it will open SMS app!
NOTE: Following section involves risk for bricking your phone. You are following these instructions on your own. I'm not responsible if your phone is bricked or any kind of phone damage.
What you need to download before you flash a Custom ROM and root your phone?
Here is a list: (You can google these files and download them)
1. Odin Multi Downloader v4.xx.exe ( Important program that will help you write the files to phone)
3. cwm-recovery-ace.tar.md5 (To install Custom boot)
4. upd_1.zip ( To root your phone)
I will recommend before you flash any Custom ROM on the phone you download your Factory image for your ACE phone from samfire.com website. Because some or other day you may wish to go back to original factory image. The Samsung Galaxy ACE is a very popular phone and because of that it has many many custom ROM's. If you google for it you will find many sites hosting the links to the custom roms. XDA-Developers is one of my favorite.
To name some of the ROM's that I have tried and liked are:
1. FirstUA ROM (No bugs were observed.)
2. Infinity ROM (Volume remains on maximum when running a radio app)
3. ICSStock V2 (Superb ICS simulation but my bluetooth device has problem )
I have tried 11 Custom ROM's and above 3 mentioned one are the one I liked most. There is also a ROM that simulates exact look of Windows Phone 7, and one with exact Touch Wiz 4 look, One with Sony Ericsson look and one with Miui look.
9-March-2012: Just upgraded my Stock ROM 2.3.4 to 2.3.6
Click the image to enlarge...