Filing tax return for H1b visa holders?

I am wondering what tax form (1040NR, 1040EZ, 1040, dual status, etc) should I file for 2013 tax return based on the following? If more than one option, what’s more beneficial?

	Been in the USA since 2008 (have been filing 1040 NR since then until now)

	Worked under OPT from Jan 2013 through Oct 2013

	Visited home in Oct 2013 (Oct 16-Nov 9) and got the H1b visa stamping

	Worked under H1b from Oct 2013 through Dec 2013


Additional question- During my visit I also got married in Oct 2013 ; however, spouse still back home.  Should I be filing as married filing separately or single?  If both choices available, what's more beneficial?



Thanks.  Hoping for a little thorough explanation.  Shall appreciate your help.  Even directing me to some other site/place where I can get my question answered shall be greatly appreciated.