Better chances of winning???

Slots or tables games such as roulette and blackjack.

Slots no way.  Vegas was built by the one-armed bandits.  Black-jack when played properly, you can bring the house odds against to a reasonable number.  Craps also if you don't press your bets and play all the prop bets.  In every game the house will hold an advantage, this is Vegas.  They are here to win.  Keno and video poker also hold big odds in house favor.  Baccarat may be a possibility.  Roulette, I don't think so. 

Blackjack, if you play correctly.

I haven't really kept detailed records of all my gambling in my 8 years in vegas, but I personally have success at low limit poker tables and know Craps is considered to be the table game with lowest house edge.   

PS like Shadowwarrior said-  slots are definitely worst odds/biggest house edge,the reason they take up 90% of all casino space is they have the best take.  

I usually stick to craps and BJ... I mainly play Craps at Mainstreet Station in downtown because of the 20X odds... If you up your odds on the passline and come bets, it reduces the house odds a little... I have seen a few players playing max odds on passline and 2-3 come bets with max odds and through the ups and downs of the game still came out ahead... with good money management, of course...