I need a new routine for Arms...Help me!

Ive got a 5 day split going on right now. M-Shoulders/Traps, W-Back, F-Legs, Sa-Chest, Su-Arms.

Ive been working out for about 4 years but never focused on arms. The first few years I would do Tri's on Chest day but never really did Bi's beyond an exercise of straight bar curls. This last year I have split my workout to have an arm day but never really did it. Maybe every other weekend I did it. I want to get serious about it because my lifts have gotten as strong as they will get with out stronger support muscles. I think I have added maybe 20 lbs to my straight bar curls so that I can do 80-90 X 10 now fresh and maybe 5 lbs a side to preacher curls up to 30 lbs a side since I started working out.

Right now my arm workout consists of doing 4 bi and 4 tri exercises alternating muscle groups. For Tri's I do Skull Crushers(French press), Dumbbell tricep extension, Some sort of cable work (straight/bent pushdown, one hand extensions, rope, etc), and Tricep kickback. For Bi's I do Preacher, Straigh bar or Db Curls, Seated or Standing hammer curls, Cable work for Bi's.

I want something that can get me more defined at least but I want strength too. I dont have "small arms", I have 16" arms, but more size is a plus too. Throw me a frickin bone.

Try this
for triceps do 4 sets each
close grip bench
overhead extension dumbell
v-bar extension
single arm extension (looks like doing a curl but extending)

bi's
4 sets each
long straight bar curls
single arm preacher curl
hammer curls
seated incline curls

Sounds good. BTW Im already doing dips on Chest day. Is it okay to hit Arms the day after Chest day?

It could hurt you in terms of growth, but everybodies different. I do arms the day after chest and I get pretty good results. If need be just do 3 exercises for tri's. My routine is as follows
day1 back
day2 shoulders
day3 rest
day4 legs
day5 chest
day6 arms
day7 rest

How do you recommend I split my workout? Due to my schedule I can only work out M,W,F,Sa,Su. How would you fill it by muscle group. Sunday is my day that is flaky b/c my workout partner rarely wants to workout then so thats why I placed arms there b/c i dont need spots.

Try it like me sort of,
Mon- back
Wed- shoulders
Fri- legs
Sat- chest
Sun- arms
This should be ok, it's really up to you. I mean you know your body better than anyone.