[Sony Xperia S, Acro S, Ion] -Harsh-:
Guys I've searched a lot of places on net and finally making a list of build.prop tweaks that i find everywhere (all at one place).. This all can really help extending the battery, improve performance and so on.....

Here are they : (would keep updating as i find more)

General Performance

debug.sf.hw=1

Edit existing line,

dalvik.vm.heapsize=48m

persist.sys.ui.hw=1

Faster Scrolling

ro.max.fling_velocity=12000

ro.min.fling_velocity=8000

Saves power

ro.ril.disable.power.collapse=1

pm.sleep_mode=1

windowsmgr.max_events_per_sec=60 (can be increased to higher values)

wifi.supplicant_scan_interval=180

Raises quality of images

ro.media.enc.jpeg.quality=100

ro.media.dec.jpeg.memcap=8000000

ro.media.enc.hprof.vid.bps=8000000

Increased Media & Streaming Performance

media.stagefright.enable-player=true

media.stagefright.enable-meta=true

media.stagefright.enable-scan=false

media.stagefright.enable-http=true

net.tcp.buffersize.default=4096,87380,256960,4096, 16384,256960 net.tcp.buffersize.wifi=4096,87380,256960,4096,163 84,256960

net.tcp.buffersize.umts=4096,87380,256960,4096,163 84,256960

net.tcp.buffersize.gprs=4096,87380,256960,4096,163 84,256960

net.tcp.buffersize.edge=4096,87380,256960,4096,163 84,256960

net.tcp.buffersize.evdo_b=4096,87380,256960,4096,1 6384,256960

Disable sending usage data

ro.config.nocheckin=1

To make the phone ring faster when dialing out

ro.telephony.call_ring.delay=0

Disable black screen issue after call

ro.lge.proximity.delay=25

mot.proximity.delay=25

Disable USB Debugging icon from Status Bar. (Just the Icon, debugging remains enabled.)

persist.adb.notify=0

Makes apps load faster and frees more ram. (Edit exsisting line)

dalvik.vm.dexopt-flags=m=v,o=y

Improve 3g data speeds

ro.ril.hsxpa=2

ro.ril.gprsclass=10

ro.ril.hep=1

ro.ril.enable.dtm=1

ro.ril.hsdpa.category=10

ro.ril.enable.a53=1

ro.ril.enable.3g.prefix=1

ro.ril.htcmaskw1.bitmask=4294967295

ro.ril.htcmaskw1=14449

ro.ril.hsupa.category=5

Update :

Increase the volume steps in-call :

ro.config.vc_call_steps=20

By Default, android offers seven audio levels for calls. This can be altered through this command , if you want to fine adjust the volume of your voice calls. This won’t increase the volume if it’s already low. But you can manage it by more precisely.

Values

Number of steps as integers. 7-20 is recommended. 7 is the default.

To Disable Boot Animation :

debug.sf.nobootanimation=1

Increase Touch responsiveness :

debug.performance.tuning=1

video.accelerate.hw=1

Add any of these at the bottom of the build.prop using ES/ROOT explorer and save it..

Edit : Change the permissions to rw-r-r after edit (thanks to LenAsh).

Reboot

UPDATED JB TWEAKS

For Faster streaming

media.stagefright.enable-player=true

media.stagefright.enable-meta=true

media.stagefright.enable-scan=true

media.stagefright.enable-http=true

media.stagefright.enable-record=true

Net speed tweaks

net.tcp.buffersize.default=4096,87380,256960,4096, 16384,256960

net.tcp.buffersize.wifi=4096,87380,256960,4096,163 84,256960

net.tcp.buffersize.umts=4096,87380,256960,4096,163 84,256960

net.tcp.buffersize.gprs=4096,87380,256960,4096,163 84,256960

net.tcp.buffersize.edge=4096,87380,256960,4096,163 84,256960

net.tcp.buffersize.hspa=4096,87380,256960,4096,163 84,256960

net.tcp.buffersize.lte=524288,1048576,2097152,5242 88,1048576,2097152

net.tcp.buffersize.hspda=4096,87380,256960,4096,16 384,256960

net.tcp.buffersize.evdo_b=6144,87380,1048576,6144, 87380,1048576

Frees More RAM

persist.sys.purgeable_assets=1

Enable surface dithering

persist.sys.use_dithering=1

[(0= off, 1= on) - dont write these] :p

Enable on screen buttons (on any rom)

qemu.hw.mainkeys=0

More to COME ~~~!! :laugh: