I'll suggest you dell studio.It has very huge hardisk space and 512 MB graphic card.So no problem for gaming.But I don't know where dell studio is available at the price bellow 50000.
If you do not have that much mone then the best is
"Sony VAIO 15.5" VPCEB16 Windows 7 Home Premium 4GB RAM 500GB HDD Laptop & Computer E Series"
Its configuration are as follows:
• Intel® Core™ i3-330M Processor 2.13 GHz
• Genuine Windows® 7 Home Premium (64-bit)
• 15.5 (39.37 cm) wide (Full-HD: 1920 x 1080) VAIO Display Plus, LED Backlight
• ATI Mobility Radeon™ HD 5650 Graphics
• Instant web browsing: Quick Web Access button
• Isolation keyboard with 19mm full key pitch and numeric keypad
It has 1GB DDR3 Graphic card best for all games
Its MRP is 49,550.So 450 less than your asking
Trust me its the best Laptop for gaming now a days