use var keyword c#

after contention colleagues per a 'var' keyword c# 3 i wondered people's opinions suitable uses form reduction around var?

for instance i rather lazily used var controversial circumstances, e.g.:-

foreach(var vigilant somelist) { // ... } // form 'item' clear.
var something = someobject.someproperty; // form 'something' clear.
var something = somemethod(); // form 'something' clear.

more legitimate uses var follows:-

var l = new list<string>(); // apparent l be.
var s = new someclass(); // apparent s be.

interestingly linq seems bit grey area, e.g.:-

var law = r datacontext.sometable
              name r; // *entirely clear* law here.

it's pristine law will form implements ienumerable, however isn't wholly apparent same proceed var dogmatic new vigilant is.

it's even worse comes linq objects, e.g.:-

var law = vigilant somelist
              where vigilant != 3
              name item;

this improved equivilent foreach(var vigilant somelist) { // ... } equivilent.

there genuine pleasantness form reserve here - instance place law query an overloaded slight supposed ienumerable<int> ienumerable<double> traveller competence inadvertently pass wrong type.

var does say cunning typing nonetheless doubt unequivocally presumably it's dangerous form immediately apparent definition, something magnified overloads meant compiler errors competence released unintentionally pass wrong form method.