The stat boost from Int is a much better value.
Strongly disagree.
9 Int vs. 5 int is only 2 extra stat points per level. 9 agility vs. 5 agility is a huge difference in reloading speed/firing speed.
If you want my opinion...
STR - Fairly important due to the STR requirement of weapons for optimal performance. Go with 3 if you plan on getting the STR implant (+1 STR) and the weapons handling perk (-2 STR requirement for all weapons) and don't want to use anything but the most basic firearms, go with 5 if you plan on the implant and perk and want to be able to use most weapons, go with at least 7 STR if you want to be able to use the heavy-duty weapons too.
Perception - Honestly, it's damn useless in Vegas. Just take ED-E with you (greatly amplifies your perception) and level your sneak and there's almost no need for Perception.
Endurance - Governs your HP and how many implants you're allowed to buy (9 total available, 1 for each SPECIAL stat, one for extra defense and one for HP regen) and your chance to resist poison attacks. I love endurance, though others look down on it.
Charisma - Governs how strong your followers are. With 1 Charisma, your followers will drop dead in seconds. With 10 charisma, they're absolutely deadly.
Intelligence- A lot of people call this the most important stat, I disagree strongly. 2 INT = one extra stat point per level.
ONE. While the difference between 1 Endurance and 10 Endurance is 180 HP points, the difference between 1 INT and 10 INT is 4.5 extra stat points per level. Just get at least 4 INT so you can get the INT perks like Comprehension and Educated and you'll be fine.
Agility - Determines reload speed and for some weapons, firing speed (usually for lever-action weapons). Leave it at 5 at least to get a perk that vastly increases reload speed.
Luck - Determines your crit rate and your success in the casinos. Most important for players that wanna be rich and use energy weapons, less important for people that want to snipe while in sneak mode or don't care about money.