Here is an idea for a great night in!

Start with thinking about a theme. Your favourite grape variety, favourite area, country, wine type, the options are countless.
Invite your best wine-loving friends for an evening of wine entertainment. A group of six is ideal. Everyone brings one bottle of wine linked to the overall theme, but with distinct differences in either price point or whereabouts or style and most importantly, where they were bought. Any background information will prove fascinating once the wines are revealed after the blind tasting, so keep hold of it.

To organise the tasting ensure you have plenty of glasses, some mild cheese and biscuits and pen and paper. (or a laptop if you must) Ensure you receive all the wines a few days beforehand and make sure they are at the correct temperature. It is preferable that the wines are decanted into generic bottles so they can't be recognised by the bottle shape. Just clean out your empty wine bottles for this purpose. Once decanted, mark the bottles with the wine they contain and then wrap them entirely in tinfoil. Mix them up and ask someone else to stick a number on each of the bottles. That way no one will know which is which. If you want to make it look really professional you can invest in some blind tasting bottle bags. I recently found some on the internet for around £10 per set of six numbered bags.

Kick off the tasting with a glass of something completely at odds with the tasting. This will break the ice nicely and ensure everyone is a bit more relaxed before going into the more serious part. Unless your tasting is Champagne, that is what you want to start with. If your tasting is themed around Champagne you might as well just get going.
Taste each wine and score it out of 5, with 5 being the best. Take notes if you wish and after all wines are scored, reveal the wines one by one. The tasting should take no more than 45 minutes, but may be longer if you wish. The object afterwards has to be to finish the bottles, although by now you may have to fight over the best.

Themes are endless. I quite like comparing six reds of the Languedoc, three wines at £6 or below and three between £10 and £18. You may be surprised at the price of your favourite. Another theme could be 'Champagne and Sparkling Wines', where you have three different Champagnes competing with three other Sparkling Wines, be it Prosecco, Californian Moet or even English Sparkling Wine.
What is important is that you taste honestly, simply to find your favourite wine.