I have VPS with 17 500 MB RAM,free -m:
# free -m
             total       used       free     shared    buffers     cached
Mem:         17500      10805       6694          0          0       5934
-/+ buffers/cache:       4871      12628
Swap:         1024       1024          0

/etc/my.cnf

max_connections=200
max_user_connections=18

innodb_file_per_table=1
local-infile=0
max_allowed_packet=268435456
open_files_limit=43762
ft_min_word_len=3

# was not there, was default 8M
key_buffer_size=1400

thread_cache_size=12
max_connections=200
innodb_buffer_pool_size=760M
join_buffer_size=16M

#was not there, was default 128k
read_buffer_size=16M

# was 512M
query_cache_size=512M
query_cache_limit=512M
table_cache=6024
table_open_cache=5000
tmp_table_size=1024M
max_heap_table_size=1024M