My favourite God has to be Lord Vinayaka (Ganesha). The second child of Lord Shiva, he was originally created to guard his consort Parvati while she bathed but ended up almost defeating the Lord himself in battle before having his head severed. He was then revived with the head of an elephant and so began his story.
Lord Ganesha is one of the more smarter and playful ones among the Hindu Gods. A famous story about him is when his brother Muruga got fooled into traversing the whole universe at the behest of his parents but the cheeky Ganesha simply went around his parents stating that his parents were indeed the universe itself! Finally someone who doesn't spend all his time meditating, saving the universe or gets himself fooled into giving boons to ill meaning Rakshasas (Demons)
Now comes the most interesting part of Lord Vinayaka. He's fat. Yes, he's fat and I always wondered why. Almost every other Hindu god is portrayed as a warrior (I even saw an image of Lord Krishna on sale near the ISKON temple sporting a six pack!) with grand weapons and all the other paraphernalia but Lord Vinayaka is always shown with a bowl full of laddus! (Sure his stomach is supposed to 'symbolise' a vast hoard of knowledge and the laddus are supposed to be knowledge to be assimilated........ yea........ok..... ) .
He's also the God who doesn't demand too much from you. All he asks of his devotees is to tell him a friendly 'Hi' before starting something new and ask for his blessing and doesn't bother you thereafter. Oh and did you know that he also protects street corners from ghosts? Hence the little Ganesha idols at the end of every street end.
All in all, its Lord Ganesh FTW if there ever was a "Who's your favourite God?" poll.