It depends if you are building it for you to enjoy or for your guest to enjoy.
If you look at the best and most well rounded for entertaining I would say cheaper TV and sofa or a few good chairs $1000 for that type stuff and decor. Then I would say Skeeball Machine (everyone loves Skeeball), a Shuttle Alley (second most used machine when we have guest), and a MAME arcade machine. Next would be a Slugfest or other pitch & bat and that should put the total around $5000 so far.
Then I would buy 3 or 4 Data East or William's System 11 machines and a couple earlier SS or EM machines with the other $5000. No need for killer good titles for entertaining - the most played machines in our gameroom are stuff like Shaq Attack, Secret Service, Waterworld, etc.
If you are building the room more for yourself I would say mostly pins and buy what you like. But from my experience pins are not the hit in our gameroom when we have guest.
Pool Tables are a waste of space unless you love playing pool. 95% of the time they just become junk collectors so I would avoid the pool table. Jukeboxes are cool but you don't need to shell out big money for one - you can buy something decent for under $500 if you are not looking for rare / expensive ones.
It really depends on what you are trying to accomplish but one thing for sure - everyone loves Skeeball