I'd say the levels go like this:
Tipsy (talking more, giggling)
Tiddly (slightly clumsy and saying some silly things)
Liqoured up (becoming more confident, suggesting doing crazy things)
P****d up (actually doing crazy things, rambling on about complete nonsense)
Hammered (falling over, slurring, being loud, over reacting to everything, getting emotional)
Under the table (incapable of doing anything but vomiting or passing out)
I'd say I get hammered once a month, p****d up once a fortnight, liqoured up at least once every week and somewhere between tiddly and drunk twice a week.
Unfortunately I find it impossible to stay at tipsy, because when i'm tipsy I always want another drink