Compare two poker hands
Python - 774 722 707 698 685 chars
import sys
t,q,e,u='--23456789TJQKA','SDCH',enumerate,len
_=lambda c,i=0:chr(97+c[i])
def j(s):
 v,g,l=[0]*15,[0]*4,''
 for c in s:
  r,s=c[0],c[1];v[t.find(r)]+=1;g[q.find(s)]+=1
 c,h,k,m,f=0,0,[0,0,[],[],[]],0,0
 for x,i in e(v):
  for b in[2,3,4]:
   if i==b:k[b]+=[x]
 v[1]=v[14]
 for x,i in e(v):
  if i:
   c+=1
   if c==5:m,h=1,x
   if i==1:l+=_([x])
  else:c=0
 f,l,d=max(g)//5*2,l[::-1],'';z=f+m
 if z==3:d='z'+l
 if k[4]:d='y'+_(k[4])+l
 if k[2] and k[3]:d='x'+_(k[3])+_(k[2])
 if z==2:d='w'+l
 if z==1:d='v'+_([h])
 if k[3]:d='u'+_(k[3])+l
 if u(k[2])&gt;1:d='t'+_(k[2],1)+_(k[2])+l
 if u(k[2])==1&gt;u(k[3]):d='s'+_(k[2])+l
 return d or l
p=sys.argv
print(1+(j(p[1:6])&lt;j(p[6:])))

I chose to generate a string for each hand that represents it, starting with a character for the type of hand, followed by characters describing the particular variation of the type (for example, which card did you just have 4 of?), followed by the values of the remaining cards in case of a tie (if both players have the same double pair, the 5th card will have to decide who wins). I've tested it quite extensively, but I don't actually play poker, so I hope I got it right. Also, I know it's not fully golfed yet, I can probably shave off a few dozen chars later on.