My Server is called Bricked Technology.
Advantages of the server : the server is hosted professionally at Into VPS on a Sandy Bridge host with 4 gigs of memory. That's enough for about 40 people in vanilla minecraft. I don't intend to allow more than 15-20 to ever connect with all these mods. This is enough CPU power for the most complex creations, that the bigger servers will lag horribly under. (the reason is that Sandy Bridge CPUs are the most powerful CPUs per CPU core that money can buy, and minecraft is mostly limited by the speed of just 1 CPU). As the server grows I have my credit card ready to purchase an even more powerful host.
This means that when you build stuff here, you MATTER. There aren't 300 people playing, so anything you build will be impressive by the standards of the server. There aren't dozens of people competing for the server's limited CPU cycles, so build the biggest, grandest machines possible.
Currently, we all know each other, and have built a teleport network interconnecting our bases.
Difficulty is set to Hard, and there are hordes of monsters outside the typical base. Creepers will grief the unprepared because there are new forms of creepers that are nastier than the ones in the vanilla game. Usually, new players spawn in a hole that is difficult to escape from. This is on purpose.
Go here for information on installing the mods and connecting : www.brickedtechnology.blogspot.com
Mods currently in use :
IndustrialCraft 2 1.24, Buildcraft 2.2.4, Redstone Power 2 prerelease 3
Elemental Creepers 1.5, Wireless Redstone, Railcraft
Portal Gun, WW 2 Guns, Teleport Pipes
Power Converter by Power Crystal
And we've got a custom texture pack that is under developement that will cause all of these mods to use 64x64 high definition textures.
This is more mods than almost any other server. As of the current version, the client is quite stable and the server does not crash. I do have the server auto-restart every 6 hours in order to ensure it remains glitch free.
How do these mods all fit together? Well, the veteran player already knows about the core 3 mods and how they interact (IC2/RP2/BC).
Elemental Creepers add challenge. They do a LOT of damage over time. The only way to be safe is you have to make sure to completely protect your work area from all angles with fencing and lighting or even better, electric fences. Or Tesla coils and sentry guns.
Wireless Redstone provides a handy way to set up remote controls that are wireless, such as security systems to get into a base.
Portal Gun fits surprisingly well. The gun is fairly cheap and a lot of fun, but not overpowered compared to the travel you can do with quantum armor. We have portal networks set up with platforms designed to connect bases by portal gun. However, portals are temporary and you cannot enter a chunk that is unloaded by the server, limiting long distance travel. Portal mod adds working SMP sentry guns, sounds and all that help to protect your base. Portal also adds various cool portal themed-items, like the music disks.
WW2 Guns : while WW2 isn't the theme of the server, this mod has been around for a while and it is very stable and low resource. The guns are fairly balanced (they all cost lots of iron to build and use, which is the most valuable resource as veteran players know) and they provide a way to gun down those elemental creepers without harming the surrounding terrain. (unlike the mining laser, which damages blocks if you miss) The ammunition takes up a fair amount of room in inventory, though, providing balance.
Teleport Pipes : these allow you to drain oil and resources from remote areas. At the moment, if there are unloaded chunks between you and your base, buildcraft pipes will cease functioning once the items enter unloaded chunks. However, I am considering making teleport pipes only available for liquids, leaving solids for railcraft.
Railcraft allows you to build an automated rail track between your factories and your quarries. Currently, teleport pipe does the same thing but I intend to eventually disable those. Railcraft also will allow us to interconnect our settlements with high speed paths as railcraft adds high speed rails.
Power Converter is a valuable mod that interconverts between BuildCraft and Industrialcraft energy. You can burn oil for power or run quarries off of nuclear energy.
Rules : No entropic griefing. If you make changes to someone's base, they need to increase the complexity of the base. Feel free to experiment with nuclear energy all you like, just make sure it is in wilderness areas or at least not near someone else's base.