ye the penny one is good, as the only way you can get them back is by downing your drink to get the coin back.
also, theres 'the peg game' where its the same as the penny one except you have to put the peg on the person without them knowing, if they catch you doing it, you down your drink. Also quite funny seeing people walk round with a clothes peg stuck to their t-shirt. if you get pegged then you down your drink and the pegs is yours for revenge.
the one our lads play none stop and dont even have to say is in play! (its not a game- its a religion to us) is called 'hallelujah' it simply is when you finish your drink and the glass is empty you have to tap someone with the glass before you put it on the table and let go, same for when you move any empty glass that been drunk out of (lifitng it off a surface) or moving your own to go fill it up somewhere else. If someone notices this all they need to do is shout 'HALLELUJAH' It sounds simple to avoid but my god people forget so much! Especially new people! but they always seem to love playing it. The best time is when someone puts their empty drink down! and people shout 'HALLELUJAH!!' then you fill it up and they down it like a hero!......but dont tap anyone again and get hallelujahed AGAIN! hilarious! this happened at a posh dinner in spain with like 12 of us round a big table! the volume of our shout on the second downing made the whole place turn around! ahhhh memories! You also end up purposley talkin to mates as they finish drinks to put them off or say 'cant you just put this over there' or 'fill this up on your way please mate.' I find myself tapping my glass all the time even at home whilst eating dinner, my rents are used to it now lol. Even if im alone havin a drink i tap myself with the glass and just say 'tap' sometimes fml....im so lonely haha