I just can't decide wich genie lamp. Please help me!

I use Longevity because it starts with 15 Dex and that increases the time genie buffs last. I have my genie full of buffs because I find it handy in tight situations. However for PvP you may want to choose Infliction because then you can teach it Thunderstorm and that's crazy handy against heavy classes. Relentless Courage coupled with a spark is deadly too. ^^

Depends on what you want it for.

solo PvP, Group PvP, PvE, etc.

I got the Zeal genie, you need to get at least 40 points into Mag, for the 4th skill slot

I'm going to be rebuilding mine later however.

I'm using 2 type of genies in PvP： Infliction (Str) and Zeal (Mgc).

Infliction or "red genie" starts off with a 15 str bonus which is greatly useful later on for thunderstorm, no doubt the best attack to pick off BM/Barb on the ground (hits for 4k+ at lvl 80 with your metal debuff). You can also throw in few more other skills like Rumbling Thunder ( does about 2/3 dmg of the Thunderstorm in the air only ).
The stats you want to achieve mainly for this genie is 12 vitality and the rest in str ( ignore dex/magic ）and the affinities are 7 fire for thunderstorm and the other skills is completely your choice.

The second genie that is really useful is Zeal or "yellow genie" it starts off with 15 magic making it great for learning mutiple skills (up to 5 or more at lvl 80+) and it has INCREDIBLE regeneration speed ( about x2-3 times what a pure str genie has) So it's good for spamming skills during long battles or PvE situation. This type of genie should mainly focus on defensive skills making you very hard to kill. I recommend having Holy Path / Tree of Protection / Blood clot as the basic skills but you can choose others as you move on. There's multiple combination of build you can make for this genie but i currently use a 5 skill based one it seems to work well for me: 80 magic the rest in vit . To be honest I find the Dex for self buff genies quite useless it's true it makes the skill a bit better but i find it more useful to have multiple skills and be able to spam them.

Also at 40 magic you get to learn 4 skills, 50 magic your regen speed will be upgraded to 2 energy/sec and at 80 magic you get 5 skills and a 2.6 regen speed.

In PvP these 2 genies are quite useful the Infliction is mainly vs HA ( Bm/Wb ) and the Zeal genie is great for survival saving you tons of dolls。 b:bye

P/S try getting a good genie ( one with a lot of lucky points, because each lucky points gives you 1 extra stat to invest -> VERY useful for str genies ) not to mention at 61+ lucky points it makes your genie look very hot ( final form -> except for the discipline (white) it's basically the same as the basic one you get but multiply the size by 3 with a gentle snowy trail )

if you plan to get only 4 genie skills, discipline will be your best bet.

relentless courage and ToP are a must

I strongly recommend holy path for its usefulness in getting away, going to save someone, just making a long walk shorter.