Try a meteorb, a mix of frozen orb, meteor, and fireball. Nice dual-element sorc, can handle pretty much anything in the game, specially with a good merc. Check the sorceress forum guides for stickies.
Might also want to check the fishymancer guide in the necro forum, a nice big army of skeletons might appeal to you.
I think you are asking two separate questions.
1. A good first class
2. A rusher
1. Got to go with a Fishymancer for the first one. Can play naked, good for MF but unless you fancy paying teleport charges no a great rusher.
2. While leads me on to a sorceress. Personally single tree has power but is a pain with immunes. Can I recommend Meteorb? Versitile and powerful.
And before anyone mentions single tree lightening with infinity to break immunes, as the OP mentioned first char, I thought he would be poor and a cheap option would be good.
Edit: pwnd but I give links!:grin:
Edit: PM a mod and ask nicely. They may move it for you.
The bugs and suggestions forum is normally used for bugs in the game or suggestions about how to improve the game. You'll probably get many more responses if you post in the newcomer or community forum.
As a good balance of questions 1 and 2, as Thiad sees it, would be a Trapper. They can level well as a first character through using Fire Blast, they can move quickly through Burst of Speed (though no-one will be faster than a sorc in the long run), and they have a very high damage output in the long run with Lightning Sentry and Death Sentry. They will have some difficulty in hell with lightning immunes, but for a first char, they can work untwinked, just by shopping a high mana wand and throwing sapphires into a helm, and they'll be fairly fast rushers/mfers while being reasonably safe (I'm probably biased to the safety aspect given that I play HC).
The problem with having a cold and lightening sorceress is the faster cast rates are different for cold/fire and lightening. Cold/fire is 105%, lightening is 117%. That is why cold and fire IE Meteorb or Blizzballer is easier.
I haven't any experience with a fo/cl sorc but I can say my light sorceress is much more mana intensive.
I mainly play single player (IE not battle net where duped runes abound, so I like cheap) and both my meteorbs are a pleasure to play. The vanilla one is untwinked with the cheapest gear and doesn't have insight. (Ok, I have a Tals armour but it was a gift after wearing armour with two sapphires in it until very late hell), the rwm/rrm version is a 200fcr meteorb. That shows you can start off with low end stuff and work your way up.
Fair play to the assassin suggestion; my first character was an assassin. But I suggested Fishy and Meteorb for the reason that they both have very good guides. I haven't paid any attention to assassin guides (which is why that first char is retired :wink3 with the exception of the Budget assassin. Mine is in early Hell because I keep getting distracted. But she is killing.
I say go with a lightning sorc. She will kill meph easily and Tele without using hardly any mana. All you need is a tals set do get started. Eventually if you build enough wealth get an infinity for your merc. I kill meph before he stops laughing. Then with the infinity merc you can run pits, pindle shenk and eldritch with great ease. After you build a little more wealth get yourself a skelliemancer, with a high corpse explosion you will run baal like a champ. Put some crushing blow on your merc and you will kill baal in about 30 seconds.
From this point on make whatever you want. You have your MF and rushers.:thumbsup:
Strangly not many people have suggested Druid, but if this is your first ever character I would definitly suggest it, as it gives you a taste of a magic skill tree (elemental), a summoning skill tree (summoning) and a mele tree (shapeshifting) by playing a druid as your first charcter you can figure out which style of play you prefer, the only not coverd really are assasin and amazon, which are fairly unique character types if you ask me