Should i call ??
 

Just sat down at the table /no stats on vilain.

Poker Stars - No Limit Hold'em Cash Game - $0.50/$1 Blinds - 6 Players - (LegoPoker Hand History Converter)

SB: $141.40
Hero (BB): $99.50
UTG: $42.35
MP: $279.00
vilain (CO): $26.15
BTN: $5.90

Preflop: Hero is dealt 9[img]/images/graemlins/club.gif[/img] J[img]/images/graemlins/heart.gif[/img] (6 Players)
UTG checks, MP folds, vilain calls $1.00, 2 folds, Hero checks

Flop: ($2.50) 4[img]/images/graemlins/club.gif[/img] 9[img]/images/graemlins/diamond.gif[/img] 5[img]/images/graemlins/heart.gif[/img] (3 Players)
<font color="red">Hero bets $2.50</font>, UTG folds, vilain calls $2.50

Turn: ($7.50) 5[img]/images/graemlins/diamond.gif[/img] (2 Players)
<font color="red">Hero bets $5.00</font>, vilain calls $5.00

River: ($17.50) 4[img]/images/graemlins/spade.gif[/img] (2 Players)
Hero checks, <font color="red">vilain bets all-in for $17.65</font>, Hero ???

Re: Should i call ??
 

yes. this is usually only 5x or a bluff (sometimes an overpair i guess), and i think it's a bluff more than 33% of the time.