KerbalFrost Small Showcase (Mod by Manu93cxz)
If you want a realistic cryogenic effect and maximum launch immersion, you need to check out KerbalFrost by Manu93cxz.
It dynamically generates that dense cryogenic boil-off vapor venting from the tanks, builds up procedural frost while waiting on the pad, and then beautifully shatters the ice into flying fragments upon ignition.
KerbalFrost is available on CKAN, GitHub and SpaceDock.
Also, huge thanks to Manu93cxz for bringing this awesome feature back to life!