Best silicone, etc,.. for around shower door.?

GE makes a real good silicone. All silicone is a challenge to get a nice neat bead but it works great. Clean and dry and don t get it wet for at least 24 hrs. Polyseam seal is a good caulk but NOT for what your doing. It has latex in it and will deteriorate over time in a wet situation like you have. Now if your looking for a colored caulk to use at the base of your tub you can use a latexed based caulk there. You can get a nice looking caulk job there but it won t last as long as a silicone sealer. GL