Scrabble can be cutthroat, or it can be fun. I've done both, and have discovered that I prefer playing it for style over decimating my opponent (though that's fun as well, if circumstances present themselves).
If you take a look at the rules, they don't actually forbid non-English words, just proper nouns and words that require punctuation such as hyphens and apostrophes.
So just for the heck of it, we accumulated a batch of dictionaries and language guides - not to look up words to play, but to prove the words we used were legitimate words. We ended up with a game that used English, French, German, Latin, Swedish, Klingon, Romulan, and Vulcan. Greek letters are also very useful to know.
Most of the words we used were English, of course, since that's the language we think in. But the others were handy for using up letters when no obvious English word was possible.
Scrabble point value:
1p: A, E, I, L, N, O, R, S, T, U
2p: D, G
3p: B, C, M, B
4pt: F, H, V, W, Y
5pt: K
8pt: J, X
10pt: Q, Z
Scrabble best synergy tiles with each letter are:
A-I (Crucial, Hail, etc.)
B-M (Submit, Comb, etc.)
C-R (Architect, Crest, etc.)
D-N (Band, Wednesday, etc.)
E-A (Aeroplane, Bead, etc.)
F-L (Calf, Flutter, etc.)
G-N (Bang, Sign, etc.)
H-S (Sharp, Touchstone, etc.)
I-O (Coin, Judicious, etc.)
J-A (Jaguar, Ajar, etc.)
K-N (Bank, Know, etc.)
L-F (Flutter, Calf, etc.)
M-B (Submit, Comb, etc.)
N-G (Bang, Sign, etc.)
O-U (Continuous, Count, etc.)
P-R (Price, Corp, etc.)
Q-U (Bouquet, Quest, etc.)
R-C (Architect, Crash, etc.)
S-T (Stick, Bats, etc.)
T-C (Conduct, Bankruptcy, etc.)
U-Q (Quest, Bouquet, etc.)
V-C (Covet, Vocal, etc.)
W-A (Watt, Awesome, etc.)
X-T (Next, Atxondo, etc.)
Y-A (Yawn, Day, etc.)
Z-T (Waltz, Aztec, etc.)